CN207019652U - A kind of valve drive gap measurement apparatus - Google Patents

Abstract

The utility model discloses a kind of valve drive gap measurement apparatus, including valve stepper motor, input shaft angular displacement sensor is installed on valve stepper motor, the output shaft of valve stepper motor is connected with valve reducing gear, the output of valve reducing gear is pivotally connected to the valve body axle of valve body, and output shaft angular displacement sensor is also associated with valve body axle.The utility model can measure the concrete numerical value of the drive gap of valve, and it is compensated, to improve the precision of valve.

Description

A valve transmission clearance measuring device

technical field

The utility model belongs to the field of fluid machinery, in particular to a valve transmission gap measuring device.

Background technique

A high-precision valve is an important fluid flow control component. It generally uses a stepping motor to drive the valve core to rotate through a precision reducer to change the fluid flow area to achieve precise flow regulation. There are mainly two types of high-precision valves used in pulp and papermaking applications. One is a valve used for longitudinal quantitative control of paper, which is called a "quantitative valve" (see patent CN200971996Y for the mechanical structure of the valve); It is a dilution water valve used in the quantitative control of the dilution water hydraulic headbox banner (the mechanical structure and control of the valve are shown in patents CN20100590897.X, CN201410616320.X, CN201420552085.X, CN201420553135.6, and CN201420552373.5). The precision of this kind of valve is expressed by "step", "step" refers to the minimum positioning length unit of the valve, taking a valve with 10000 step precision as an example, it means that the valve has 10000 steps within the range of 0-90° opening Operation steps, the angle increment of the valve opening for each operation step is 0.009°, the more steps of the valve, the higher the precision of the valve.

In order to ensure that the valve has sufficient positioning accuracy, this kind of valve is mostly driven by a stepping motor or a servo motor. Although the motor has sufficient positioning accuracy, the motor transmits the rotational motion to the valve shaft through the reducer and the coupling. There are multiple mechanical transmission links, and there are transmission gaps (also called return gaps) between these mechanical components. Since the valve is often positioned forward and reverse during work, the mechanical gap problem leads to the loss of valve accuracy. However, the problem of mechanical clearance of valves is often ignored at present, resulting in low precision of valves. It is difficult to meet the requirements of the modern process industry for high-precision flow regulation, so it is necessary to study this problem to solve the problem of the transmission gap (also called the return gap) of the valve and improve the accuracy of the valve.

Utility model content

The purpose of the utility model is to provide a valve transmission clearance measuring device to overcome the problems in the prior art. The utility model can measure the specific value of the transmission clearance of the valve and compensate it to improve the accuracy of the valve.

In order to achieve the above object, the utility model adopts the following technical solutions:

A valve transmission gap measurement device, including a valve stepping motor, an input shaft angular displacement sensor is installed on the valve stepping motor, the output shaft of the valve stepping motor is connected with a valve deceleration mechanism, and the output shaft of the valve deceleration mechanism is connected to a valve body The valve body shaft is connected with an output shaft angular displacement sensor on the valve body shaft.

Further, the input shaft angular displacement sensor is installed on the tail shaft of the valve stepping motor.

Further, the output shaft of the valve stepping motor is connected to the valve reduction mechanism through a coupling.

Further, the valve deceleration mechanism, the output shaft angular displacement sensor and the valve body are all installed on the stand.

Compared with the prior art, the utility model has the following beneficial technical effects:

The utility model device is equipped with an input shaft angular displacement sensor on the tail shaft of the valve stepping motor, and an output shaft angular displacement sensor is installed on the valve body shaft. By detecting the input shaft angular displacement sensor and the output shaft angular displacement sensor when the valve returns The difference between the theoretical rotation angle and the actual rotation angle is used to obtain the size of the mechanical transmission gap of the valve, and then compensate the mechanical transmission gap of the valve.

The utility model can realize the measurement of the mechanical gap of the valve, and can obtain the number of control pulses of the stepping motor corresponding to the mechanical gap; the method of judging is to use two different values to respectively represent the opening or closing state of the valve opening adjustment direction, In particular, the 0 and 1 numbers that are easy to implement in the controller are used to indicate the valve opening state, and the difference between the value of the current valve opening adjustment direction and the value of the last valve opening adjustment direction is used; the current opening The method of making a difference between the direction and the last opening direction to judge whether the current opening state is consistent with the last opening direction is simple and feasible in the algorithm, and more effective than complicated procedures; the current opening direction and the last opening direction are in the valve When the opening adjustment is reversed from last time, by increasing the number of pulses sent by the stepping motor, the compensation of the mechanical transmission gap of the valve is realized in the software, and the accuracy of the valve is improved. Compared with the traditional method of ignoring the mechanical transmission gap, it is beneficial Improve the accuracy of the valve. After measuring the transmission clearance of the valve within the opening range, according to the different values of the mechanical transmission clearance at each point, different amounts of mechanical clearance compensation are performed. The valve does not need to install an encoder on the valve shaft during actual operation. Compared with the closed-loop The high-precision valve (see patent CN201310019466.1, closed-loop high-precision quantitative valve) has the advantage of low cost and can ensure the precision of the valve.

Description of drawings

Fig. 1 is a structural representation of the utility model;

Fig. 2 is a work flow diagram of the utility model.

Among them, 1. Input shaft angular displacement sensor, 2. Valve stepping motor, 3. Valve deceleration mechanism, 4. Bench, 5. Coupling, 6. Valve body shaft, 7. Output shaft angular displacement sensor, 8. body.

detailed description

Below in conjunction with accompanying drawing, the utility model is described in further detail:

Referring to Fig. 1, a valve mechanical transmission gap measuring device, the valve stepper motor 2, valve deceleration mechanism 3, shaft coupling 5, valve body 8 are removed during measurement, and installed on the bench 4 of the utility model testing device . A valve stepping motor 2 is installed on the platform 4 of the measuring device, and an input shaft angular displacement sensor 1 is installed on the tail shaft of the valve stepping motor 2 to detect the actual rotation angle input by the valve stepping motor 2; The output shaft of the motor 2 is connected to the valve deceleration mechanism 3, the output shaft of the valve deceleration mechanism 3 is connected to the valve body shaft 6 through a coupling 5, and the output shaft angular displacement sensor 7 is installed on the valve body shaft 6 for detection and detection. The actual rotation angle output to the valve shaft 6 after passing through transmission mechanisms such as a reduction mechanism, the output shaft angular displacement sensor 7 is installed on the platform 4 , and the valve body 8 is installed on the platform 4 .

If the internal space of the valve actuator is sufficient, the bench 4 is not needed, and the measurement is performed directly on the valve actuator, and the test device is appropriately simplified, and the input shaft angular displacement sensor 1 is installed on the valve stepping motor 2, and used To detect the rotation angle of the valve input end; the output shaft angular displacement sensor 7 is installed on the valve body shaft 6 to detect the rotation angle of the valve output end.

If the parts of the valve are reduced and there is no coupling 5, the valve body shaft 6 is directly connected to the valve deceleration mechanism 3, and the output shaft angular displacement sensor 7 is installed on the valve body shaft 6 to detect the rotation angle of the valve output shaft. Within the scope of protection declared by the new model.

In the utility model, an input shaft angular displacement sensor 1 is installed on the tail shaft of the valve stepping motor 2, and an output shaft angular displacement sensor 7 is installed on the valve body shaft 6. By detecting the input shaft angular displacement sensor 1 and the output shaft angular displacement sensor 7 The difference between the theoretical angle of rotation and the actual angle of rotation during the return stroke of the valve is used to obtain the size of the mechanical transmission gap of the valve. And have nothing to do with valve motor type, deceleration mechanism type, change the type of motor and deceleration mechanism type all can not break away from the protection domain of the present utility model.

The method for measuring the mechanical transmission gap of a valve comprises the following steps:

Step 1: Collect the mechanical parameters such as the step angle θ _s of the valve stepping motor 2 and the reduction ratio (input speed: output speed) n of the valve reduction mechanism 3 .

Step 2: Use the valve mechanical transmission gap measuring device designed by the utility model to make the valve stepping motor 2 rotate in one direction until the valve body shaft 6 produces an effective rotation, and at this time the valve transmission mechanisms have been attached to each other; then Then make the valve stepping motor 2 reversely rotate until the valve shaft produces effective rotation (when the valve stepping motor 2 just starts to reverse, due to the mechanical transmission gap, the valve body shaft 6 is in a static state), through the input shaft angular displacement sensor 1 Measure the actual rotation angle θ ₁ of the valve stepping motor 2; measure the actual rotation angle θ ₂ ' of the valve body shaft 6 through the output shaft angular displacement sensor 7, and calculate the theoretically corresponding rotation angle θ ₂ ' of the valve body shaft 6 The number m of control pulses sent by the valve stepping motor 2, m is expressed by formula (1):

The number k of control pulses corresponding to the actual rotation angle θ _of the valve stepping motor 2 is expressed by formula (2):

The valve stepper motor 2 control pulse number j corresponding to the mechanical transmission gap of the valve is expressed by formula (3):

j＝|k-m| (3)

Step 3: Change the opening of the valve body 8, traverse all the opening values of the valve body 8 from fully open to fully closed, repeat step 2, and use the valve mechanical transmission clearance compensation device of the utility model to measure different opening conditions The mechanical transmission gap of the lower valve corresponds to the number of control pulses of the valve stepping motor 2.

Referring to Figure 2, after measuring the mechanical transmission clearance of the valve, the input shaft angular displacement sensor 1 and the output shaft angular displacement sensor 7 can be removed when the valve is in normal operation. The method of valve mechanical transmission clearance compensation is as follows:

First judge whether clearance compensation is needed, use the values of 0 and 1 to indicate the direction of valve opening adjustment (larger or smaller), and use the difference between the current valve opening state and the previous valve opening adjustment direction state, when the two When the difference between them is 0, it means that the current valve opening state is the same as last time, and there is no need to compensate the valve mechanical transmission clearance; when the difference is not 0 (ie -1 or 1), the current opening direction of the valve is the same as the previous On the contrary, mechanical transmission clearance compensation is required. The specific compensation method is: make the stepping motor of the valve send more control pulses of the stepping motor equal to the value of the mechanical transmission gap on the basis of the preset number of positioning step control pulses, so that the mechanical transmission gap of the valve can be compensated. If the positioning direction of the valve is the same as last time, there is no need for mechanical transmission clearance compensation.

The operating process of the present utility model is described in detail below:

First measure the mechanical transmission clearance of the valve:

Step 1: Depending on whether the space inside the valve can install the input shaft angular displacement sensor 1 and the output shaft angular displacement sensor 7, if it can be installed, install the input shaft angular displacement sensor 1 on the shaft of the valve stepper motor 2 to detect For the input shaft rotation angle, install the output shaft angular displacement sensor 7 on the valve body shaft 6 to detect the output shaft rotation angle; if there is not enough space inside the valve, remove the valve stepper motor 2, deceleration mechanism 3, and coupling 5 and the valve body 8 are installed on the bench 4 of the testing device. Install the input shaft angular displacement sensor 1 on the shaft of the valve stepper motor 2 to detect the input shaft rotation angle, and install the output shaft angular displacement sensor 7 on the valve body shaft 6 to detect the output shaft rotation angle.

Step 2: Make the valve stepping motor 2 rotate in one direction until the valve body shaft 6 produces an effective rotation, at this time the valve transmission mechanism has been attached to each other; then make the valve stepping motor 2 rotate in the opposite direction until the valve body The shaft 6 produces effective rotation (when the stepper motor just starts to reverse, the valve shaft is in a static state due to the mechanical transmission gap), the actual rotation angle θ _{1 of the stepper motor is measured through the input shaft angular displacement sensor 1} ; through the output shaft angle The displacement sensor 7 measures the actual rotation angle θ ₂ ' of the valve body shaft, and calculates the number m of control pulses sent by the stepping motor corresponding to the rotation angle θ ₂ ' of the valve body shaft in theory, and m is represented by formula (1):

The number k of control pulses corresponding to the actual rotation angle θ _of the stepping motor is expressed by formula (2):

The number j of stepper motor control pulses corresponding to the valve mechanical transmission gap is expressed by formula (3):

j＝|k-m| (3)

Step 3: Change the opening of the valve body, traverse all the opening values of the valve body from fully open to fully closed, repeat step 2, and use the valve mechanical transmission gap compensation device of the utility model to measure the valve under different opening conditions. The mechanical transmission gap corresponds to the number of control pulses of the stepper motor.

After measuring the valve stepper motor 2 control pulse number j equivalent to the mechanical transmission clearance of the valve, it is judged according to the running direction of the valve that the valve needs to perform clearance compensation during operation. The steps are as follows:

Step 1: Determine whether gap compensation is required for the current opening adjustment.

The method of judging is to use two different numbers to represent the state of the valve opening adjustment respectively. In particular, the 0 and 1 numbers that are easy to implement in the controller are used to represent the valve opening state, and the value of the current valve opening adjustment direction is compared with the The value difference of the last valve opening adjustment direction;

Assume that the last adjustment direction state M00 of the valve is expressed by the numerical values M1 and M2 respectively, M1 indicates that the valve is closed smaller, and M2 indicates that the valve opening is increased.

Assume that the adjustment direction state M01 of the valve is represented by the numerical values M1 and M2 respectively, M1 indicates that the valve is closed smaller, and M2 indicates that the valve opening is increased. The number of pulses for stepper motor positioning is N1.

Make a difference between M01 and M00. When the difference M=0, it means that the current adjustment direction of the valve is consistent with the last adjustment direction, and there is no need for gap compensation; when M≠0, it means that the current adjustment direction of the valve is opposite to the last adjustment direction. , gap compensation is required.

Step 2: Calculate the number N2 of pulses sent to the stepping motor at the time.

The expression of N2 is shown in (4):

Step 3: Send N2 positioning pulses to the valve stepping motor driver to realize the current positioning operation.

Among them, M00, M01, M1, M2, M, N1, N2, j, k, m, n, θ ₁ , θ _s , θ ₂ ' are operation symbols of the method of the present utility model, and changing the names of symbols cannot depart from this The scope of protection of utility models.

In particular, in order to facilitate program processing in a binary program controller, the value ranges of M1 and M2 are limited to two states of 0 and 1. Make a difference between M01 and M00, according to whether the difference is 0, if it is 0, it means that the current opening adjustment direction is consistent with the last opening adjustment direction, if it is not 0, it is judged that the current opening adjustment direction is inconsistent with the last adjustment direction , if it is replaced by other numerical values, it cannot depart from the protection scope of the present utility model.

Claims (4)

1. a kind of valve drive gap measurement apparatus, it is characterised in that including valve stepper motor (2), valve stepper motor (2) On input shaft angular displacement sensor (1) is installed, the output shaft of valve stepper motor (2) is connected with valve reducing gear (3), valve The output of door reducing gear (3) is pivotally connected to the valve body axle (6) of valve body (8), is also associated with exporting axis angular displacement on valve body axle (6) Sensor (7).

A kind of 2. valve drive gap measurement apparatus according to claim 1, it is characterised in that described input shaft angle position Displacement sensor (1) is arranged on the tailing axle of valve stepper motor (2).

A kind of 3. valve drive gap measurement apparatus according to claim 1, it is characterised in that the valve stepper motor (2) output shaft is connected to valve reducing gear (3) by shaft coupling (5).

A kind of 4. valve drive gap measurement apparatus according to claim 1, it is characterised in that described valve reductor Structure (3), output shaft angular displacement sensor (7) and valve body (8) are installed on stand (4).