JP2022175753A - measuring device - Google Patents

Abstract

To certainly measure the degree of contamination even if positional deviation of a light emitting element or a light receiving element occurs.SOLUTION: A measuring device comprises: piping in which liquid passes, the piping being at least partially light transmissive material; a light irradiation unit having a first substrate provided with a first light emitting element that continuously irradiates the liquid passing through the piping with light and a second light emitting element adjacent thereto; a light receiving unit having a first light receiving element that continuously receives the light radiated from the first light emitting element and passing through the liquid, a second light receiving element that is provided adjacent to the first light receiving element and continuously receives the light passing through the liquid in the same manner, and a second substrate that is provided with the first light receiving element and the second light receiving element; a housing that is provided with the first substrate and the second substrate; and a contamination degree measuring unit that measures the liquid based on an output signal from the light receiving unit. The piping is inserted into holes in the housing, and the first light emitting element and first light receiving element and the second light emitting element and second light receiving element are arranged with the piping therebetween. The optical axes of the first light emitting element and the first light receiving element substantially match each other, and the optical axes of the second light emitting element and the second light receiving element substantially match each other.SELECTED DRAWING: Figure 1

Description

The present invention relates to measuring devices.

Patent Document 1 discloses a particle detection signal that is a signal generated by amplifying an electrical signal converted by a light receiving section by a first magnification, and a second magnification that is smaller than the first magnification of the electrical signal converted by the light receiving section. Disclosed is a measuring device that generates a signal for measuring the degree of contamination of a liquid based on a bubble detection signal, which is a signal generated by amplifying at .

JP 2016-45033 A

In the invention described in Patent Document 1, light emitted from one light-emitting element is received by two light-receiving elements, so it is necessary to apply light to the two light-receiving elements evenly. However, when the measuring device is installed in construction machinery and operated under high temperature, the mounting substrate of the light emitting element and the light receiving element is thermally deformed, so that the light does not reach the two light receiving elements evenly, and the degree of contamination increases. Measurement may not be possible.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a measuring apparatus capable of reliably measuring the degree of contamination even when a light emitting element or a light receiving element is misaligned.

In order to solve the above problems, the measuring device according to the present invention includes, for example, a pipe through which a liquid passes, at least a part of which is formed of a light-transmitting material, and a pipe that passes through the pipe. a first light emitting element for continuously irradiating the liquid with light; a second light emitting element provided adjacent to the first light emitting element; and a second light emitting element provided with the first light emitting element and the second light emitting element. a light irradiation unit having a substrate; a first light receiving element for continuously receiving light emitted from the first light emitting element and passing through the liquid; and adjacent to the first light receiving element. a second light-receiving element for continuously receiving light emitted from the first light-emitting element and passing through the liquid; and the first light-receiving element and the second light-receiving element. a light receiving unit having a second substrate; a housing in which the first substrate and the second substrate are provided; a contamination degree measuring unit that generates a signal, the housing is provided with a hole, the pipe is inserted into the hole, and the first light emitting element and the first light receiving element are and the second light emitting element and the second light receiving element are arranged with the pipe interposed therebetween, and the optical axis of the first light emitting element is aligned with the first light receiving element and the optical axis of the second light emitting element substantially coincides with the optical axis of the second light receiving element.

According to the measuring device according to the present invention, the first light emitting element and the first light receiving element and the second light emitting element and the second light receiving element are arranged with the pipe interposed therebetween, and the optical axis of the first light emitting element and the The optical axis of the first light receiving element substantially coincides, and the optical axis of the second light emitting element substantially coincides with the optical axis of the second light receiving element. As a result, the degree of contamination can be reliably measured even if the positions of the light-emitting element and the light-receiving element are misaligned.

The contamination level measurement section may measure the contamination level of the liquid based on a difference between an output signal from the first light receiving element and an output signal from the second light receiving element. This makes it possible to measure the degree of contamination while removing the effects of air bubbles.

According to the present invention, the degree of contamination can be reliably measured even if the positions of the light-emitting element and the light-receiving element are misaligned.

1 is a cross-sectional view showing an outline of a measuring device 1; FIG. 2 is a block diagram showing an outline of the electrical configuration of the measuring device 1; FIG. It is a figure which shows the outline of the conventional measuring apparatus 100. FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The measuring device of the present invention is provided at a desired position of a device that performs a desired operation using liquid, such as construction machinery and hydraulic equipment, and measures the degree of contamination of the liquid.

FIG. 1 is a cross-sectional view showing the outline of the measuring device 1. As shown in FIG. In addition, in FIG. 1, the hatching which shows a cross section is partially abbreviate|omitted. The measuring device 1 mainly has a light irradiation section 10 , a light receiving section 20 , a housing 30 and a pipe 39 .

The light irradiation section 10 mainly has two light emitting elements 11 and a substrate 15 on which the light emitting elements 11 are provided. The two light emitting elements 11 are provided adjacent to each other. The light emitting element 11 is, for example, an LED, and irradiates the inside of the pipe 39 with light.

The light receiving section 20 mainly has two light receiving elements 21 and a substrate 25 provided with the light receiving elements 21 . The light-receiving element 21 is, for example, a photodiode (PD), and detects transmitted light due to light irradiation.

The light emitting element 11 and the light receiving element 21 are arranged with a pipe 39 interposed therebetween. Also, the optical axis ax1 of the light emitting element 11 substantially coincides with the optical axis ax2 of the light receiving element 21 .

Hereinafter, the light emitting element 11 and the light receiving element 21 on the upstream side are referred to as a light emitting element 11a and a light receiving element 21a, and the light emitting element 11 and the light receiving element 21 on the downstream side are referred to as a light emitting element 11b and a light receiving element 21b. The optical axis ax1 of the light emitting element 11a substantially coincides with the optical axis ax2 of the light receiving element 21a, and the optical axis ax1 of the light emitting element 11b substantially coincides with the optical axis ax2 of the light receiving element 21b.

In FIG. 1, the optical axis ax1 of the light emitting element 11 is aligned with the optical axis ax2 of the light receiving element 21, but the optical axis ax1 and the optical axis ax2 may not be aligned. It may be slightly deviated from the axis ax2.

At least a part of the pipe 39 is made of a light-transmitting material, and the liquid to be measured, such as oil or water, passes through the pipe 39 . The light emitting element 11 irradiates the portion of the pipe 39 made of the light transmissive material with light from one side, and the light receiving element 21 receives the light from the other side.

The pipe 39 may be entirely made of a light-transmissive material, or partially formed with a window for introducing and leading light. In FIG. 1, the pipe 39 is entirely made of a light transmissive material.

The pipe 39 is provided inside the housing 30 . The housing 30 mainly has a first housing 31 , a second housing 32 and a third housing 33 .

The first housing 31 is provided with holes 31a provided at both ends thereof, and a hole 31b connecting the two holes 31a. The central axis of the hole 31a and the central axis of the hole 31b are substantially aligned.

A pipe 39 is inserted into the hole 31b, and a second housing 32 is inserted into each of the holes 31a. A portion of the third housing 33 is inserted outside the second housing 32 into the hole 31a. A female threaded portion 31c is formed in the hole 31a, and the male threaded portions 32a and 33a formed on the outer peripheral surfaces of the second housing 32 and the third housing 33 are screwed together so that the second housing 32 and the third housing 33 are screwed together. 3 housing 33 is provided in the hole 31a.

Holes 32b and 33b are provided in the second housing 32 and the third housing 33, respectively. The holes 32b and 33b communicate with the hollow portion of the pipe 39 and serve as flow paths for the liquid.

In this embodiment, the second housing 32 and the third housing 33 are separate members, but the second housing 32 and the third housing 33 may be one member.

The first housing 31 has recesses 31d and 31e. A substrate 15 is provided in the recess 31d, and a substrate 25 is provided in the recess 31e. A hole 31g is provided in the bottom surface of the recess 31d, and the light emitting element 11 is provided in the hole 31g. A hole 31f is provided in the bottom surface of the concave portion 31e, and the light emitted from the light emitting element 11 enters the light receiving element 21 through the pipe 39 and the hole 31f.

FIG. 2 is a block diagram showing an outline of the electrical configuration of the measuring device 1. As shown in FIG. The measuring device 1 has a contamination degree measuring unit 41 , an output unit 43 and a display unit 45 . Further, the light irradiation section 10 has a driving circuit 17 and the light receiving section 20 has an amplifier 27 .

The drive circuit 17 drives the two light emitting elements 11 to make the outputs of the two light emitting elements 11 the same. The drive circuit 17 includes a constant current circuit or the like that keeps the amount of light emitted from the light emitting element 11 constant. The drive circuit 17 causes the light emitting element 11 to emit light continuously. The two light receiving elements 21 continuously receive the light emitted from the light emitting element 11 and passing through the liquid. The drive circuit 17 may include an APC circuit that feeds back the amount of light received by the light receiving element 21 .

Output signals from the two light receiving elements 21 are amplified by amplifiers 27, respectively. The amplifier 27 that amplifies the signal of the light receiving element 21a is referred to as an amplifier 27a, and the amplifier 27 that amplifies the signal of the light receiving element 21b is referred to as an amplifier 27b.

The output signal of the light receiving element 21a is input to the adder/subtractor 28 after being amplified by the amplifier 27a, and the output signal of the light receiving element 21b is input to the adder/subtractor 28 after being amplified by the amplifier 27b. An adder/subtractor 28 provides a differential output of the light receiving element 21 (21a, 21b). Since the output signal from the light receiving element 21 is a continuous signal, the differential output of the light receiving element 21 is also a continuous signal.

The operation output is input to the contamination level measuring section 41 . Then, the contamination level measurement unit 41 measures the amount of particles contained in the liquid flowing through the pipe 39 based on the differential output of the light receiving element 21 . Hereinafter, the principle of measuring the amount of particles by the contamination degree measuring unit 41 will be described, taking as an example the case where the particles D are flowing in the flow path toward the position of x1→x5.

Since the outputs of the light-emitting elements 11a and 11b are the same, the amount of light entering the light-receiving element 21 is the same when there is no impurity particle such as the particle D, and the differential output is zero. When the particle D is at the position x1, the amount of light entering the light receiving element 21 is the same, so the differential output is zero.

When the particle D is at the position x2, the amount of light received by the light receiving element 21a is blocked by the particle D and becomes smaller than the amount of light received by the light receiving element 21b, and the differential output has a negative value. When the particle D reaches the position x3, the amount of light entering the light receiving element 21 becomes the same again, and the differential output becomes zero. When the particle D comes to the position x4, the amount of light received by the light receiving element 21b is blocked by impurities, and the differential output has a positive value, contrary to the case where the particle D is at the position x2. Then, when the particle D passes through the optical path and reaches the position x5, the light intensity of the light receiving element 21 becomes the same and the differential output becomes zero.

In this way, the particles D block one optical path to each of the two light receiving elements 21, so that the differential output signal outputs waveforms having positive and negative values, and the number of waveforms increases in proportion to the amount of the particles D. . As a result, the contamination level measurement unit 41 measures the amount of particles contained in the liquid, that is, the contamination level.

In addition, the contamination level measurement unit 41 removes the effects of air bubbles from the differential output signals from the two light receiving elements 21 . Bubbles are output as a larger signal than particles in the differential output signal. The process of removing the effects of air bubbles by the contamination degree measuring unit 41 will be described below.

The contamination degree measurement unit 41 acquires the differential output signal output from the adder/subtractor 28, amplifies the differential output signal by a first magnification, and performs full-wave rectification to generate a particle detection signal. Further, the contamination degree measurement unit 41 amplifies the differential output signal by a second magnification, performs full-wave rectification, and generates an air bubble detection signal.

When bubbles are detected, the crest value of the differential output signal becomes larger than when particles are detected. By setting the second magnification lower than the first magnification, in the bubble detection signal, the particle detection result does not appear as a waveform, and only the bubble detection result appears as a waveform.

The contamination level measurement unit 41 generates an air bubble suppression signal based on the air bubble detection signal. The bubble suppression signal is a signal having two values of Low and High. When the value of the bubble detection signal is not equal to or greater than the threshold, the bubble suppression signal is set to Low, and when the value of the bubble detection signal is equal to or greater than the threshold, the bubble suppression signal is set to High.

When the bubble suppression signal is Low, the contamination level measurement unit 41 integrates the particle detection signal to obtain a contamination level measurement signal. When the bubble suppression signal is High, the contamination level measurement unit 41 obtains the pollution level measurement signal by integrating the particle detection signal immediately before the bubble suppression signal becomes High.

Then, the contamination level measurement unit 41 determines the contamination level of the liquid based on the contamination level measurement signal. For example, the contamination level measurement unit 41 determines the contamination level based on the value of the contamination level measurement signal using an evaluation method such as the NAS grading method or the ISO cleanliness level. Then, the contamination level measurement unit 41 outputs the determined contamination level to the output unit 43 . The output unit 43 outputs the contamination degree to the display unit 45 .

An output unit 43 is connected to the contamination level measurement unit 41 . A display, a processing device, a storage device, a communication device, a construction machine, and the like are connected to the output unit 43 . The measurement results are displayed on a display, stored in a storage device, or output to a construction machine via a communication machine and displayed on the construction machine. In this embodiment, a display unit 45 is connected to the output unit 43 . Note that the output unit 43 may output the measurement result to an external output device or the like via a network (whether wired or wireless).

Returning to the description of FIG. The measuring device 1 is installed in a construction machine or the like, and the measuring device 1 is used in an environment of 100 degrees or more during operation of the machine. In a high-temperature environment, the substrates 15 and 25 are thermally deformed, which causes the light-emitting element 11 and the light-receiving element 21 to move in a direction substantially perpendicular to the optical axes ax1 and ax2 (horizontal direction in FIG. 1).

However, since the light-emitting element 11 and the light-receiving element 21 correspond 1:1, even if the light-emitting element 11 and the light-receiving element 21 are misaligned, strong light emitted from near the front of the light-emitting element 11 will not be emitted. Incident into the light receiving element 21 .

According to the present embodiment, even if the optical axis ax1 and the optical axis ax2 are misaligned due to thermal deformation, the strong light irradiated from near the front of the light emitting element 11 is incident on the light receiving element 21. Therefore, the measurement apparatus 1 can reliably measure the degree of contamination.

For example, when light emitted from one light emitting element 11 is received by two light receiving elements 21 as in the conventional measuring apparatus 100 shown in FIG. Arrange the optical axis ax1. The strong light emitted from near the front of the light emitting element 11 does not enter the two light receiving elements 21 , and the light emitted obliquely from the light emitting element 11 enters the light receiving element 21 .

Therefore, if the positions of the light emitting element 11 and the light receiving element 21 are displaced due to thermal deformation, light will not enter one of the two light receiving elements 21 . For example, as shown by the dotted line in FIG. 7, when the two light receiving elements 21 shift to the left side of the paper, light enters the light receiving element 21 on the right side of the paper, but does not enter the light receiving element 21 on the left side of the paper. As a result, the measuring device 100 may not be able to measure the degree of contamination.

On the other hand, in the present embodiment, the light emitted from one light emitting element 11 is received by one light receiving element 21, so that the light emitted from the light emitting element 11 is reliably incident on the light receiving element 21. Therefore, it is possible to prevent a situation in which the degree of contamination cannot be measured due to thermal deformation.

Moreover, according to the present embodiment, since there are two sets of the light emitting element 11 and the light receiving element 21, it is possible to measure the degree of contamination while removing the effects of air bubbles. As a result, the degree of contamination can be measured with high accuracy.

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and design changes and the like are also included within the scope of the gist of the present invention. . For example, the above embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the described configurations. Also, part of the configuration of the embodiment can be replaced with the configuration of another embodiment, and it is possible to add, delete, or replace the configuration of the embodiment with another configuration. In addition, in the present invention, the term "substantially" is not limited to the case of being exactly the same, but is a concept that includes errors and deformations to the extent that the identity is not lost.

Reference Signs List 1: measuring device 10: light irradiation units 11, 11a, 11b: light emitting element 15: substrate 17: drive circuit 20: light receiving units 21, 21a, 21b: light receiving element 25: substrates 27, 27a, 27b: amplifier 28: adder/subtractor 30: housing 31: first housing 31a: hole 31b: hole 31c: female threaded portion 31d, 31e: concave portion 31f, 31g: hole 32: second housing 33: third housing 32a, 33a: male threaded portion 32b, 33b: Hole 39: Piping 41: Contamination measuring unit 43: Output unit 45: Display unit 100: Measuring device

Claims (2)

a pipe through which a liquid passes, at least a part of which is made of a light-transmitting material;
a first light emitting element for continuously irradiating the liquid passing through the pipe with light; a second light emitting element provided adjacent to the first light emitting element; and the first light emitting element and the second light emitting element. A light irradiation unit having a first substrate provided with
a first light-receiving element for continuously receiving light emitted from the first light-emitting element and having passed through the liquid; a light-receiving unit having a second light-receiving element that continuously receives light that is continuously irradiated and that has passed through the liquid; and a second substrate on which the first light-receiving element and the second light-receiving element are provided;
a housing provided with the first substrate and the second substrate;
a contamination level measurement unit that generates a signal for measuring the contamination level of the liquid based on the output signal from the light receiving unit;
with
A hole is provided in the housing, and the pipe is inserted into the hole,
The first light emitting element and the first light receiving element are arranged across the pipe,
The second light-emitting element and the second light-receiving element are arranged with the pipe interposed therebetween,
the optical axis of the first light emitting element substantially coincides with the optical axis of the first light receiving element,
The measuring device, wherein the optical axis of the second light-emitting element substantially coincides with the optical axis of the second light-receiving element. 2. The contamination level measurement unit according to claim 1, wherein the contamination level measurement unit measures the contamination level of the liquid based on a difference between an output signal from the first light receiving element and an output signal from the second light receiving element. measuring device.

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