JPH0592672U - Load cell two-stage switching control device - Google Patents

Abstract

(57) [Summary] [Purpose] A wide range of torque tests can be performed continuously, and precise lock adjustment of the small torque detection load cell is not required. [Structure] A torque detection arm 1 provided with a small torque detection load cell 2 and a large torque detection load cell 3
A limiter 18 that makes the torque signal of the load cell 2 a constant value when the torque exceeds the rated range of the load cell 2, and a limiter 10 that outputs the torque signal of the load cell 3 when the torque exceeds the rated range, and the limiters 18 and 10 A continuous torque signal c is output by an adding amplifier 11 that adds the output signals a and b of the lock mechanism 5
When the torque exceeds the rated range, it operates and eliminates the need for precise lock adjustment for merely protecting the load cell 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a load cell two-stage switching control device capable of continuously detecting a wide range of torque.

[0002]

[Prior Art]

 For load cells that detect torque in dynamometers, etc., 1. In the case of running resistance control, a small load cell is used because the torque range is generally smaller than the dynamometer rating.

2. Since the dynamometer system with electric performance has a large torque range, a large load cell is used.

3. A large load cell should be used when performing full performance measurements due to the large torque range.

As described above, the load cells are switched for the purpose of improving accuracy by using the load cells suitable for the test method.

Since the load cell is selected while the dynamometer or the like is stopped, it is impossible to continuously perform a wide-range torque test, and a switching operation for selecting the load cell is required.

Therefore, the applicant of the present invention has previously provided a small torque detection load cell 2 and a large torque detection load cell 3 on the torque detection arm 1 as shown in FIG. When the rated range of the small torque detection load cell 2 is exceeded, a lever 4 provided in the middle part of the arm 1 is locked, and a lock mechanism 5 is provided to prevent the torque beyond the rated range from being applied to the small torque detection load cell 2. On the other hand, the signal of the large torque detection load cell is clipped by the limiter 10 so as to be output when the torque exceeds the rated range of the small torque detection load cell 2, and the signal a from the amplifier 8 and the signal b from the limiter 10 are output. We proposed a load cell two-stage switching device that can obtain a continuous torque signal c from small torque to large torque by adding with the amplifier 11 ( Jpn. Pat. Appln. No. 4-32293). In FIG. 3, reference numerals 6 and 7 represent strain amplifiers for amplifying the signals of the load cells 2 and 3.

[0008]

[Problems to be solved by the device]

 By the way, in the previous proposal above, when the torque exceeds the rated value of the small torque detection load cell, the signal from the small torque detection load cell is applied to the small torque detection load cell by the lock mechanism so that the signal becomes a constant value. The torque must be locked.

Therefore, the lock mechanism is required to be adjusted very severely and the adjustment is not easy, and the lock mechanism is required to be precise and expensive.

The present invention has been made in view of the above problems of the related art, and an object of the present invention is to provide a load cell capable of continuously performing a wide range of torque tests without requiring precise lock adjustment. It is to provide a two-stage switching control device.

[0011]

[Means for Solving the Problems]

 In order to achieve the above object, the load cell two-stage switching control device according to the present invention comprises a torque detecting arm having a small torque detecting load cell and a large torque detecting load cell arranged in the axial direction, and a torque detecting arm for detecting a small torque. A first limiter that outputs a signal from the small torque detection load cell as a constant value when the load cell exceeds the rated range, and a second limiter that outputs the torque signal from the large torque detection load cell when the torque exceeds the rated range. Limiter, an adder circuit for adding the output signals of the first and second limiters, and a lock mechanism for locking the torque applied to the small torque detection load cell when the torque exceeds the rated range. ..

[0012]

[Action]

 When torque is applied to the torque detection arm, the arm bends and a signal is output from the small torque detection load cell and the second large torque detection load cell, but until the torque exceeds the rated range of the small torque detection load cell. The second limiter does not output, and only the signal from the small torque detection load cell is output from the first limiter. When the torque exceeds the rated range, the output of the first limiter becomes constant, and the second limiter outputs the limited signal of the large torque detecting load cell.

Therefore, the outputs from the first and second limiters are added by the adder circuit to obtain a continuous torque signal from a small torque to a large torque.

On the other hand, when the torque exceeds the rated range, the lock mechanism operates to lock the torque applied to the small torque detecting load cell, so that the small torque detecting load cell is protected from the torque. Since the lock mechanism only protects the small torque detection load cell, no severe adjustment is required.

[0015]

【Example】

 An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the configuration of the embodiment. The same components as those shown in FIG. 3 of the related art are designated by the same reference numerals, and the duplicated description will be omitted.

In FIG. 1, reference numeral 15 denotes a lock mechanism for protecting the load cell 2 by locking the arm 4 when the torque exceeds the rated range of the small torque detection load cell 2, which is the same as the conventional lock mechanism 5 of FIG. It does not require severe adjustment.

Reference numeral 18 denotes a limiter which receives a torque signal from the strain amplifier 6 of the load cell 2 and, when the torque exceeds a rated value of the load cell 2, outputs a signal a limited to a certain value as shown in FIG. is there. The clip operating point and the slice operating point of the limiters 10 and 18 are the same as or slightly lower than the operating point of the lock mechanism.

Reference numeral 11 denotes an addition amplifier that adds the output signals a and b of the limiters 10 and 18 and outputs a torque signal c.

Next, the operation of this embodiment will be described.

It is assumed that the torque applied to the arm 1 gradually increases from zero. When the torque is within the rated range of the small torque detection load cell 2, the output signal a of the limiter 18 to which the torque signal from the strain amplifier 6 of the load cell 2 is input is proportional.

When the torque reaches the rated value of the load cell 2, the output signal a of the limiter 18 becomes constant as shown in FIG. Simultaneously with or slightly after this, the lock mechanism 5 operates to protect the load cell 2 from torque.

On the other hand, the limiter 10 to which the signal from the strain amplifier 7 of the large torque detection load cell 3 is input, outputs the output signal b as shown in FIG. 2 when the torque reaches the rated value of the load cell 2.

Therefore, the torque signal c output from the adding amplifier 11 is continuous from a small torque to a large torque, as shown in FIG. 2, even if the adjustment of the lock mechanism 5 is not severe.

[0025]

[Effect of the device]

 Since the present invention is configured as described above, it has the following effects.

(1) It is not necessary to select a load cell, and a wide range of torque tests can be continuously performed.

(2) It is not necessary to severely adjust the lock mechanism, which facilitates the adjustment and makes it possible to use a cheap lock mechanism.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a configuration of an embodiment.

FIG. 2 is a characteristic diagram of signals of respective parts in the embodiment.

FIG. 3 is an explanatory diagram of a configuration of a conventional example.

[Explanation of symbols]

 1 ... Torque detection arm 2 ... Small torque detection load cell 3 ... Large torque detection load cell 5 ... Lock mechanism 6, 7 ... Strain amplifier 10, 18 ... Limiter 11 ... Addition amplifier (addition circuit)

Claims (1)

[Scope of utility model registration request] 1. A torque detection arm having a small torque detection load cell and a large torque detection load cell arranged in the axial direction, and a torque detection arm from the small torque detection load cell when the torque exceeds the rated range of the small torque detection load cell. The first limiter which outputs a signal as a constant value, the second limiter which outputs a signal from the large torque detection load cell when the torque exceeds the rated range, and the output signals of the first and second limiters are added. And a lock mechanism that locks the torque applied to the small torque detection load cell when the torque exceeds the rated range, and is capable of continuously detecting from small torque to large torque. Two-stage load cell switching control circuit.