TW201309896A - System for detecting parameters applied to a compressor piston - Google Patents

Abstract

The present application refers to a system for detecting parameters applied to a compressor piston, comprising simultaneously detecting certain parameters of said compressor piton, such as: piston speed, piston position and occurrence of impact between said piston and the plate of valves. The system for detecting parameters applied to a compressor piston comprises at least an axially movable arrangement driven by an electric engine (9); at least a sensor (5) comprising at least a displaceable portion (51) and at least a fixed portion (52); at least an electronic circuit comprising at least a processing core (10), and said system differs from the conventional systems in that said electronic circuit further comprises at least a filtering module (11); said output signal (SS) of sensor (5) is sent to said filtering module (11); and said filtered signal (SF) of the filtering module (11) is sent to said processing core (10).

Description

System for detecting parameters applied to compressor pistons

This application relates to a system for detecting parameters applied to a compressor system (which belongs to a cylinder/piston assembly). More specifically, the system of the present invention, which is preferably applied to a piston driven by a linear engine, is capable of detecting at least one of a piston speed or a piston position (in the compressor cylinder). Preferably, the system now described achieves simultaneous detection of said parameters.

It is known to those skilled in the art that a cylinder/piston assembly (specifically, when associated with a linear compressor) can be advantageously employed in a cooling system or the like.

In such applications, a cylinder/piston assembly is physically secured to a plate (or structure) at which an inlet valve and a discharge valve for the liquid to be compressed are disposed. At the same time, the plate (or structure) actually defines the displacement path of a piston.

Therefore, a linear engine that forces the piston to move should displace the piston to prevent it from colliding (impacting) the "valve plate." To this end, it is desirable that a linear engine only shifts the piston in a reduced path relative to the total shift path.

At the same time, the efficiency of a cooling system, among other things, is in particular equal to the actual course of a piston traveling in a cylinder, that is, the greater the reduction in the displacement of the piston, the cooling system (and the compression) The efficiency of the machine itself is lower.

Therefore, ideally, the linear engine can not cause the piston to The displacement of the piston is as large as possible in the event of any form of collision between the "valve plates". To this end, it is necessary to introduce a system and/or device intended to perform this control (whether installed in the linear engine or installed in the piston/valve assembly).

Current state of the art includes different systems and/or devices for achieving the above objectives, that is, intended to control/manage a linear engine such that the linear engine displaces a piston in a safe and efficient manner. In general, each of these solutions involves a feedback system that controls the supply of power to the linear engine based on certain parameters, and thus controls piston displacement.

One of the most known solutions includes monitoring at least one of the parameters of the linear engine itself. In this solution, the current and voltage values of a linear engine act as feedback parameters for the linear engine. Even on the one hand, these solutions are simple and inexpensive (after all, idle sensors and/or converters are not used), while on the other hand, they exhibit low accuracy and inefficiency (after all, due to existing The lack of precision requires reducing the actuation path of the piston.

It is also known to use a separate sensor associated with a piston/cylinder assembly to detect a solution to certain parameters of the assembly.

A first example of such a solution is described in document BR PI 0704947-1, which teaches a piston position recognition system based on an electromagnetic flow change sensor (SVF). The system is particularly suitable for use in a linear engine driven piston/cylinder assembly that is moved by a magnetic field (between the engine and the piston) or that is coupled to at least one magnet or the like. In this system, the activity The movement of the plug (and thus the movement of the magnet coupled to the piston) produces a magnetic oscillation proportionally that can be measured by the SVF attached to the piston. Since the magnetic oscillation can be related to the instantaneous position occupied by a piston, the travel of the piston can be stopped and reciprocated before the final collision of the piston with the "valve plate". Although the concept of this system is functional, it should be observed that the system has some aspects that are suitable for improvement. One aspect of the improvement is related to the complexity of measuring the actual cylinder size and the position of the "valve plate", because when determining the piston shifting path generated by the oscillation of the magnetic field, this information must be considered in advance and SVF position.

A second example of such a solution is described in document BR PI 0301969-1, which relates to a piston position recognition system based on an accelerometer type sensor. In this case where magnetic parameters are not required to be considered, the piston position is measured by a pressure stimulus applied to the accelerometer, wherein the stimuli are generated by contacting or vibrating the piston. The accelerometer is of the piezoelectric type and its terminal portion is connected to the power supply of the linear engine by the same signal amplifier circuit, thus causing direct "interference" (feedback) with the linear engine. This concept also includes aspects that can be improved, in which it is emphasized that the accelerometer exhibits an optimized function after a collision; therefore, such systems are limited to applications that are capable of physical contact and/or piston vibration.

These two examples are particularly suitable for controlling a linear engine (associated with a piston/cylinder assembly) based on the two parameters of the piston positioning and the collision state of the piston. It is obvious that the first concept illustrated in the document BR PI 0704947-1 can be better applied to a defined range of operations, while the document BR PI The second concept illustrated in 0301969-1 can be better applied to another defined range of operations. In any event, the details disclosed in these documents merely illustrate structural changes in which an SVF detects a single parameter of the piston/cylinder assembly to drive a linear engine associated with the assembly (closed feedback system).

However, none of these examples of design and assembly can detect both the displacement speed and the transient piston position.

Therefore, it is known to those skilled in the art that it is necessary to add some specific sensors, such as the known "Hall's cells".

In short, and according to the specific literature, "Hall Unit" includes a sensor intended to measure the velocity and angular displacement of a subject. However, it is also possible to use a "Hall Unit" in a piston/cylinder assembly (which also allows detection of very low speeds). It has been observed that this type of application is not feasible because, in addition to the fact that the cost of implementing this application and its maintenance is extremely high, this type of application also requires extremely complicated adjustment circuits.

In view of the above, it is apparent that there is a need to develop a system that is capable of accurately, reliably and simultaneously detecting more than one parameter present in a cylinder/piston assembly.

Accordingly, it is an object of the present invention to provide a system for detecting parameters applied to a compressor piston that basically includes a single sensor.

Furthermore, it is a further object of the present invention to provide a system that is capable of simultaneously detecting at least two parameters relating to a compressor piston.

Specifically, a further object of the present invention is to detect piston speed, piston position, and the "valve plate" (or similar structure) of the piston and the compressor. The eventual collision event. In this regard, it is an additional object of the present invention to provide a parameter detection system for a compressor piston that allows for a rapid initial metering of the piston path (in its respective cylinder).

Performing such other and other objects by the presently proposed system for detecting a piston applied to a compressor, the system comprising at least one configuration capable of being axially moved by an electric engine; at least one sensor comprising At least one displaceable portion and at least one fixed portion; at least one electronic circuit comprising at least one processing core. The moveable configuration basically includes at least one piston, at least one link, and at least one guide. The displaceable portion of the sensor is secured to the moveable configuration. The sensor output signal is sent to the processing core.

The system for detecting a parameter applied to a compressor piston is different from the similar system in that the electronic circuit further includes at least one filter module; the sensor output signal is sent to a filter module; One of the filtering modules is sent to the processing core via the filtered signal.

According to the concept of the present invention, the processing core simultaneously receives a sensor output signal and the filtered signal from the filter module.

Preferably, the piston speed parameter is measured by the sensor output signal frequency, and the piston positioning parameter is measured by the output signal strength. As for the parameter of the collision event between the piston and the valve plate, the parameter is measured by analyzing the noise present in the sensor output signal and is displayed in the filtered signal from the filter module.

Preferably, the noise analysis displayed in the filtered signal from the filter module includes the harmonics of the higher order level present in the filtered signal. Line analysis. Further preferably, the analysis of the noise shown in the filtered signal from the filter module is performed in the processing core.

The sensor can be coupled to an electromagnetic shield as needed and in accordance with the concepts of the present invention.

The invention will now be described in more detail based on the following figures.

The basic concept of the invention includes implementing an electromagnetic flow change sensor (including a portion adapted to shift and a fixed portion) and analyzing the output signal of the sensor. Preferably, the analysis occurs in an electronic circuit that is capable of being under normal conditions and under optimized conditions (after the output signal of the sensor passes through a filter, wherein only about a piston The signal spectrum of the analysis of the position at which the "valve plate collides" is correlated to interpret the output signal of the sensor.

Thus, in accordance with the basic concepts of the present invention, a system for detecting a parameter applied to a compressor piston is capable of measuring an axial displacement speed of the piston, estimating a relative position of the piston (in the cylinder), and detecting the An event of a collision between the piston and the valve plate.

1, 2, 3 and 4 illustrate a preferred embodiment of the invention. According to this preferred embodiment, it can be noted that a piston (which belongs to a compressor) is preferably used, but not limited to, for liquid compression, which is suitable for use in conventional cooling systems, and functionally and with the piston The drive engine (also belonging to a compressor) is associated with a component of a group of interconnects.

In this regard, FIG. 1 illustrates a movable configuration that generally includes a piston 1, a link 2, and a guide body 3. In this configuration, the link 2 is disposed in The piston 1 is between the guide body 3.

At the same time, in accordance with a preferred embodiment of the present invention, a sensor 5 is provided which is responsible for reading the parameters associated with the movement of the movable configuration (specifically, the axis with the piston 1 in a cylinder (not shown) Move related parameters). The sensor 5 preferably includes an electromagnetic flow rate change sensor and is comprised of at least one displaceable portion 51 and a fixed portion 52. The reason that the displaceable portion 51 of the sensor 5 can be considered "displaceable" is that the displaceable portion 51 is associated with the movable configuration (directly or indirectly), the movable configuration including the piston 1, the connection Rod 2 and guiding body 3. As for the fixed portion 52 of the sensor 5, the fixed portion 52 can be fastened to any fixed portion of a compressor.

Preferably, the displaceable portion 51 of the sensor 5 includes a permanent magnet that preferably has axial magnetization and is attached to the guide body 3 by a first support member 4.

Preferably, the fixed portion 52 of the sensor 5 includes a coil (the electrical conductor disposed at a toroidal coil) is preferably supported by a structure by a second support member 6. Further preferably, the fixed portion 52 of the sensor 5 is disposed in a shield 7 for reducing interference from an electromagnetic field of the compressor engine and is fastened to the compressor by a structure 8. Fixed part (not shown).

According to a preferred embodiment of the invention, the axial displacement of the movable configuration preferably causes the displaceable portion 51 of the sensor 5 and the fixed portion 52 of the sensor 5 to approach each other in a cyclic manner and then keep away. A voltage of the fixed portion 52 of the cyclic motion inducing sensor 5 of the shiftable portion 51 of the sensor 5 generates a voltage, and the voltage can be regarded as an output signal of the sensor 5.

FIG. 3 schematically illustrates a magnetic flux "drawing diagram" of one of the displaceable portions 51 of the sensor 5. It can be noted from this figure that the speed and positioning of the displaceable portion 51 of the sensor 5 relative to the fixed portion 52 of the sensor 5 can be based on the voltage induced in the fixed portion 52 of the sensor 5. The estimate, that is, the speed of the movable configuration (and therefore the speed of the piston 1) is proportional to the intensity of the output signal of the sensor 5.

As described previously, the main embodiment of the present invention allows analysis of the output signal of the sensor 5. Preferably, the analysis is carried out through different concepts.

Therefore, the output signal of the sensor 5 (hereinafter referred to as the SS signal) is sent to an electronic circuit that basically includes at least one processing core 10 and includes at least one filter module 11.

Preferably, the processing core 10 includes a (preferred) electronic microprocessor or a (preferred) electronic microcontroller.

Further preferably, the filter module 11 includes a simple RC circuit (low pass filter) or an RLC circuit (high pass filter). The filter module 11 can be incorporated into the processing core 10 itself, as desired, with sufficient processing capabilities to perform signal filtering functions.

It is further preferred that the processing core 10 is directly responsible for powering the engine 9 of the compressor (not shown).

It can be noted from FIG. 4 that the SS signal is sent directly to the processing core 10 and to the filtering module 11. It can also be observed that the filtered signal SF from the filter module 11 is also sent to the processing core 10.

Therefore, it can be concluded that the processing core 10 receives and analyzes two major differences. signal. The SS signal allows estimation of the position (signal amplitude) and speed (signal frequency) of the piston 1. The SF (filtered signal) allows an event to check for a collision between the piston 1 and the valve plate (not shown).

In this regard, in the case of no collision (Fig. 6.1) and the case of collision (Fig. 6.2), the SF filtered signal (which includes the type of bandpass filter band or low-pass type (analog or digital) The SS signal of the electronic filter, wherein the dominant frequency is attenuated, has a distinctly different waveform. Instantly decompose these waveforms mathematically and decompose the results (mainly higher order harmonics (Figure 7.2)) by the processing core (10) to determine collision avoidance (mainly in the processing core 10 control for the engine The best strategy for the case of a 9 power feed.

In Figures 7.1 and 7.2, the difference between the harmonics of the higher order in the case where the collision does not occur and the case where the collision occurs are clearly shown.

In addition, it should be recognized that one of the signal differences between the case where the collision does not occur (Fig. 6.1 and Fig. 7.1) and the case where the collision occurs (Fig. 6.2 and Fig. 7.2) is mainly due to the movable configuration during the collision occurrence. The vibration (and therefore the vibration of the displaceable portion 51 of the sensor 5) is caused because the vibration can generate a magnetic field having a noise (and therefore an SS output signal) which can be confirmed by the filter module 11 And analyzed by the processing core 10.

Preferably, the system for detecting parameters applied to a compressor piston is capable of simultaneously detecting the three parameters (speed, position, and collision), wherein the speed and position of the piston 1 is obtained based on the SS signal. And an event of collision between the piston 1 and the valve plate is obtained by analyzing harmonics of the SF filtered signal.

Based on the principles of the concept and the executive function, it can be observed that it can be used immediately (for the entire functioning of a compressor) and/or for measuring and applying the initial course of the piston 1 for detecting the application to a compressor piston. The system of parameters.

After describing a preferred exemplary embodiment, it should be understood that the scope of the invention encompasses other variations. The present invention is defined only by the content of the patent application (including the equivalent equivalents).

1‧‧‧Piston

2‧‧‧ Connecting rod

3‧‧‧Guidance

4‧‧‧First support

5‧‧‧Sensor

6‧‧‧second support

7‧‧‧Shield

8‧‧‧ structure

9‧‧‧ engine

10‧‧‧ Processing core

11‧‧‧Filter module

51‧‧‧Displaceable part

52‧‧‧Fixed part

SF‧‧‧ filtered signal

SS‧‧‧ output signal

Figure 1 illustrates an enlarged perspective view of a piston (in conjunction with its linkage and sensor); Figure 2 illustrates a schematic cross-sectional view of the (assembled) assembly illustrated in Figure 1; Figure 3 illustrates the detection One of the cross-sectional views of one of the sensors applied to the parameters of a compressor piston, magnetic flux "drawing diagram"; Figure 4 illustrates one of the systems for detecting parameters applied to a compressor piston Figure 5 illustrates one of the signals measured by the sensor for detecting a system applied to a compressor piston; Figures 6.1 and 6.2 illustrate before and after the piston collides with its "valve plate", respectively. An example of one of the signals measured by the sensor and filtered by the system for detecting parameters; and Figures 7.1 and 7.2 illustrate the sensor before and after the piston collides with its "valve plate", respectively. An example of a bit level that measures and is harmonically filtered by the system for detecting parameters.

1‧‧‧Piston

2‧‧‧ Connecting rod

3‧‧‧Guidance

4‧‧‧First support

6‧‧‧second support

7‧‧‧Shield

8‧‧‧ structure

51‧‧‧Displaceable part

52‧‧‧Fixed part

Claims (9)

A system for detecting parameters applied to a compressor piston, comprising: at least one axially moveable configuration driven by an electric engine (9); at least one sensor (5) including at least one a shiftable portion (51) and at least one fixed portion (52); at least one electronic circuit comprising at least one processing core (10); the movable configuration generally comprising at least one piston (1), at least one connecting rod (2) and at least one guiding body (3), wherein the displaceable portion (51) of the sensor (5) is attached to the movable configuration; and the output signal of the sensor (5) (SS Is sent to the processing core (10); the system for detecting parameters applied to a compressor system is characterized in that the electronic circuit further comprises at least one filter module (11); the sensor (5) The output signal (SS) is sent to the filter module (11); the filtered signal (SF) of the filter module (11) is sent to the processing core (10). The system of claim 1 for detecting a parameter applied to a compressor piston, wherein the processing core (10) simultaneously receives the output signal (SS) of the sensor (5) and the filter module (11) The filtered signal (SF). The system of claim 1 for detecting a parameter applied to a compressor piston, wherein a velocity parameter of the piston (1) is measured by a frequency of the output signal (SS) of the sensor (5). The system of claim 1 for detecting a parameter applied to a compressor piston, wherein a positioning parameter of the piston (1) is measured by an intensity of the output signal (SS) of the sensor (5). The system of claim 1 for detecting a parameter applied to a compressor piston, wherein the filtered signal (SF) is used to measure a parameter of a collision event between the piston (1) and the valve plate. A system for detecting a parameter applied to a compressor piston according to claim 1 or 5, wherein the output signal (SS) present in the sensor (5) is in the filter module (11) The analysis of the noise verified in the filtered signal (SF) measures the parameter of the collision event between the piston (1) and the valve plate. The system of claim 6 for detecting a parameter applied to a compressor piston, wherein the analysis of the noise verified in the filtered signal (SF) of the filter module (11) comprises analyzing the presence of the The higher order harmonics in the filtered signal (SF). The system of claim 1 for detecting a parameter applied to a compressor piston, wherein the analysis of the noise proved in the filtered signal of the filter module (11) occurs in the processing core (10) . The system of claim 1 for detecting a parameter applied to a compressor piston, wherein the sensor (5) is applied to an electromagnetic shield (7).