Liquid level measurement

Abstract

A dispensing machine (1) and a method for determining the liquid level in the container of the dispensing machine. The dispensing machine includes: - a movable platform, such as a turntable (5); - a plurality of dispensing units (8) located on the platform, each dispensing unit including a container (4), a pump (9), and a valve (10); and - a vibration sensor (27), such as a microphone. The dispensing machine also includes an impact element (26). The platform is movable to position a selected dispensing unit (4) at a test location, wherein the dispensing unit (8) is within reach of the impact element (26).

Description

Technical Field

[0001] This disclosure relates to a dispensing machine and a method for determining the liquid level in a container of such a dispensing machine, the dispensing machine comprising a plurality of such containers. The dispensing machine may be, for example, a color mixing machine used to prepare and mix coating products of selected colors, such as paints, dyes, varnishes, clear coats, or similar compositions, using color pastes or modules. Background Technology

[0002] A tinting machine is designed to dispense and mix selected colorants or tinting pastes, optionally blending them with base paints, to prepare a paint of the desired color according to a predefined formula, for example, at a point of sale or in an auto repair shop. Tinting machines typically include containers or tanks for storing the tinting paste, and supports for carrying the containers, such as turntables or static platforms. Each container is connected via a valve, or can be connected to a pump, which can move between a pump-connected withdrawal position and a dispensing position that allows for the dispensing of metered amounts of tinting paste. Metering and dispensing must be performed with great precision to produce the correct color in a reproducible manner.

[0003] If the container becomes empty or if the quality of the toner in the container has deteriorated, the container must be refilled. To date, the toner level in the mixing machine's containers is typically monitored by tracking the amount of toner dispensed in each container. The level is then adjusted manually after refilling. This can lead to errors. For example, the operator might forget to adjust the level after refilling, or they might adjust the level in the software and then forget to refill. They might also accidentally fill the wrong container.

[0004] These errors can be prevented by monitoring the liquid level in the corresponding containers. To this end, EP 2 787 402 A1 discloses a color mixing machine with a liquid level sensor, such as a vibration sensor, ultrasonic sensor, pressure sensor, or weight sensor. US 2021 / 0017008 discloses a color mixing machine using a magnetic fluid level sensor. US 2016 / 0199866 discloses a color mixing system using a capacitive sensor. A disadvantage of these prior art systems is that each container must be equipped with a sensor connected to a data processing unit. Summary of the Invention

[0005] The purpose of this invention is to provide a simpler, more robust, reliable, and efficient system.

[0006] The objective of this invention is achieved by a dispensing machine comprising:

[0007] - Portable platform;

[0008] - Multiple distribution units located on the platform, each distribution unit including a container, pump, and valve; and

[0009] - Vibration sensors. The dispenser also includes, for example, an impact element located outside the container. The platform is movable to position a selected one of multiple dispensing units at a test location, where the dispensing unit is within reach of the impact element.

[0010] This eliminates the need for a separate measurement unit for each container. By moving the distribution unit to a test location within the reach of the impactor, a single impactor can be used for multiple containers.

[0011] In certain embodiments, the impactor is arranged to interact with a portion of the dispensing unit (e.g., the valve housing of a valve), or alternatively with a portion of the pump cylinder or a tubular line connecting the container to the valve.

[0012] The movable platform can be, for example, a turntable. The dispenser may include a control unit configured to move the platform to position a selected dispenser unit in a test position, where the dispenser unit is operatively within reach of an impactor. The dispenser units may be arranged on the platform, for example, such that containers are arranged in one or more concentric circular arrays, while all pumps and valves are arranged in a single peripheral circular array. This ensures that when a valve is in the dispenser position, its dispensing opening is always exactly above the same point. This also allows the use of a single impactor that can interact with any of the dispenser units when the respective dispenser unit is in the test position.

[0013] In certain embodiments, the vibration sensor may be, for example, one or more acoustic sensors, such as a microphone.

[0014] The impactor can be arranged, for example, to impact the valve housing of a distribution unit placed at the test location. The valve housing is typically located at the outer boundary of the distribution unit array, making the distribution unit easier for the impactor to approach. Since the valve housing, container, and piping connecting the container to the valve housing are typically made of metal, impacting the valve housing will also cause the connected container to resonate and generate vibration signals.

[0015] Optionally, the distribution unit may include an impact rod, one end of which is located at the container, such as adjacent to the container or other parts of the distribution unit, and the opposite second end of which is within reach of the impactor when the distribution unit is in the test position. When the impactor strikes the second end of the impact rod, the impact rod transmits the impact load to the container, causing the container to vibrate.

[0016] The vibration signal includes information about the quantity and / or mass of liquid in the container. For example, the container's natural frequency increases with its fill level. As a result, when resonance occurs, a filled container will produce an acoustic response at a much higher pitch than an empty container. The pitch depends on the container's fill level. The container's acoustic response is measured by an acoustic sensor (e.g., a microphone). The acoustic sensor can be connected to a data processing unit that analyzes the pitch of the acoustic response to determine the liquid level.

[0017] Alternatively, other parameters, such as degradation state, degree of sedimentation, or type of toner, can be derived from the acoustic signal. This can, for example, help to check whether the container is filled with the correct toner. For example, the Fourier transform of the vibration signal shows a first peak representing the natural frequency and one or more additional peaks indicating the quality or properties of the toner. An example of a method for analyzing acoustic signals to determine data or parameters of a material is disclosed in EP 4343 317 A1.

[0018] The impact component can be mounted to a stationary part of the dispenser, such as the inner wall of the housing or the frame of the dispenser. In this respect, stationary means that the impact component does not move with the platform (e.g., a turntable).

[0019] Alternatively, the impactor can be arranged to impact the exterior of the container, particularly the lid or top side of the container.

[0020] The impactor can be, for example, a solenoid.

[0021] The dispensing machine can be, for example, a color mixing machine for tinted paints, wherein the movable platform is a turntable, and the dispensing units are arranged on the turntable such that pumps with corresponding valves for the dispensing units are arranged in a single external circular array. When the turntable rotates to bring the dispensing units into the test position, the dispensing units can be positioned within reach of the impactor.

[0022] The present invention also relates to a method for determining the quantity and / or mass of liquid in a selected container among a plurality of containers of a dispenser using an impactor configured to vibrate the selected container and a vibration sensor. The impactor and vibration sensor may be placed outside the container. The selected container is moved relative to the sensor and the impactor to a test position within the reach of the impactor. The impactor is activated, and the resulting vibration of the container is sensed by the vibration sensor to provide a vibration signal to a control unit.

[0023] The vibration signal is then processed and analyzed, for example, through Fourier analysis or an AI module, to identify the natural frequencies and optionally additional frequency peaks. These additional peaks may contain further information about the quality of the liquid in the container, such as the type of toner and / or the degree of degradation.

[0024] The present invention also relates to a dispensing machine comprising a plurality of dispensing units, each dispensing unit including a container, a pump, and a valve having a valve housing and a valve body movable within the valve housing between a dispensing position and a withdrawing position. Each dispensing unit includes a pressure measuring device for measuring the hydraulic pressure exerted in the valve housing by a column of liquid in the container when the valve body closes the dispensing opening of the dispensing unit. The pressure measuring device may, for example, include a pressure sensor within the valve housing. Alternatively, the dispensing unit may include a flexible wall section, for example, a flexible wall section of space in the valve housing in fluid communication with the interior space of the container when the valve is in a position connecting the container to the pump. The dispensing machine includes a sensor for sensing deformation or displacement of the flexible wall section, and the dispensing unit is selectively movable to a test position where the flexible wall section is within the reach of the sensor.

[0025] Optionally, the flexible wall section is a wall portion of the space within the valve housing that is in fluid communication with the interior space of the container when the valve is in the withdrawn position, connecting the pump to the interior space of the container.

[0026] In a specific embodiment, the flexible wall section may include a plate and a flexible sleeve that provides a sealing connection between the plate and the valve body. The flexible sleeve is configured to allow movement, for example, tilting the plate in response to hydraulic pressure applied by a column of liquid in the container.

[0027] Alternatively, the flexible wall section is a replaceable part. This allows the wall section to be replaced if its elasticity decreases due to material degradation.

[0028] Each valve and pump can be controlled by a control unit to dispense the appropriate amount of liquid component, such as tinting paste metered according to a paint formulation of the selected color. The control unit can also be used to process data from one or more sensors and send signals to the operator if one of the containers needs to be refilled or if the liquid contents deteriorate.

[0029] Optionally, the container is equipped with a stirrer, such as an upright rotor with blades.

[0030] Dispensing machines according to any aspect of this disclosure are generally suitable for dispensing and mixing toners or tinting pastes for use in coating products (e.g., paints, varnishes, dyes, lacquers, inks, or similar compositions), for example, at points of sale, industrial plants, or auto repair shops. Attached Figure Description

[0031] The above aspects will be explained in more detail below with reference to the accompanying drawings, which illustrate specific embodiments by way of example, to provide further details and benefits.

[0032] Figure 1A The dispenser is shown in perspective;

[0033] Figure 1B Shown without a cover Figure 1A Distributor;

[0034] Figure 2 The container of the dispenser in Figure 1 is shown in a longitudinal sectional view;

[0035] Figure 3 Another example of a dispenser's container is shown;

[0036] Figure 4 It shows the use of Figure 2 The vibration signal generated by the system and its Fourier transform;

[0037] Figure 5 An alternative embodiment of the dispenser container of Figure 1 is shown in longitudinal sectional view;

[0038] Figure 6 An exemplary embodiment of the flexible wall section is shown;

[0039] Figure 7 The valve housing is shown Figure 6 The wall section. Detailed Implementation

[0040] Figure 1A and 1B A color mixing machine 1 for mixing and dispensing paint products is shown. The color mixing machine 1 has a dispenser housing 2 with a cover 3. Figure 1B A color mixing machine 1 without its cover 3 is shown to illustrate its internal components. The dispenser housing 2 of the color mixing machine 1 surrounds containers or jars 4 arranged in a concentric array. Each container 4 contains a specific color of color paste. The containers 4 are placed in an upright position on a turntable 5 (see [reference needed]). Figure 2 and Figure 5 The turntable 5 is coaxial with the circular array of containers 4. The color mixing machine 1 also includes a platform 6 for positioning paint cans or similar containers.

[0041] The color mixing machine 1 includes a control unit with a user interface such as a touchscreen, which communicates with the control unit, allowing the operator or user to input a desired paint color. When the user inputs a desired paint color, the control unit determines a paint formula that matches the selected paint color, for example, by selecting a paint formula from a database. The determined paint formula consists of tinting paste or a mixture of tinting pastes available in the corresponding containers 4 of the color mixing machine 1, along with an optional base paint. The control unit controls the rotation of the turntable to sequentially position the containers 4 containing the required tinting paste at dispensing positions above the paint cans on the platform 6, and controls the dispensing of the tinting paste one by one according to the paint formula.

[0042] Each container is 4. Figure 2A portion of the dispensing unit 8 is shown in longitudinal section. The dispensing unit 8 includes a container 4, a piston pump 9, and a three-way valve 10.

[0043] In the exemplary embodiment shown, container 4 includes a longitudinally cylindrical shell 11, the top of which is covered by a removable lid 12, and the bottom end is mounted to a turntable 5. An outlet 13 is provided at the bottom end of container 4. A stirrer 14 extends coaxially from the bottom end of container 4 to the removable lid 12 within the internal space 15 of the container.

[0044] The outlet 13 of container 4 is connected to piston pump 9 via tubular line 16. The tubular line 16 for the inner array of container 4 is longer than that for the outer array of container 4, such that all piston pumps 9 are arranged in a single circular array around the outer array of container 4 in the peripheral section of turntable 5.

[0045] The piston pump 9 includes an upright pump cylinder 17 and a piston 18 movable vertically within the pump cylinder 17. The piston 18 includes a piston head 19 sealed against the inner wall of the pump cylinder 17, and a piston rod 20 extending upward from the piston head 19 to the top of the pump cylinder. The piston rod 20 has a top end with a clamp 21 for engaging a drive (not shown) when the dispensing unit 8 is positioned in the dispensing position.

[0046] The three-way valve 10 has a valve housing 21 with a dispensing opening 22 and a valve body 23 within the valve housing 21. The valve body 23 is movable between a closed position (closing the container 4), a withdrawn position (connecting the container 4 to the internal space of the pump cylinder 17), and a dispensing position (closing the container 4 and connecting the pump cylinder 17 to the dispensing opening 22). When the valve 10 is in the withdrawn position, the piston 18 can move upward to draw a certain amount of liquid from the container 4, the amount being measured according to the paint formula for the desired paint color. Subsequently, the valve 10 moves to the dispensing position (closing the container 4 and connecting the pump cylinder 17 to the dispensing opening 22). Then, the piston 18 moves downward to dispense liquid from the pump cylinder 17 into a container on the platform 5.

[0047] Container 4 contains a certain amount of liquid 24, particularly tinting paste for color coatings. The liquid level is monitored to ensure timely refilling of container 4 and to prevent incorrect refilling.

[0048] The color mixing machine 1 is equipped with a solenoid impactor 26 and a microphone 27. The impactor 26 is positioned at a test location on the outer edge of the turntable and is substantially radially directed toward the center of the turntable 5.

[0049] To measure the liquid content in container 4, a turntable is rotated to move dispensing unit 8 to a test position, where valve housing 21 is within reach of solenoid impactor 26. Solenoid impactor 26 does not move with the turntable 5 but has a fixed position within the housing 2 of the color mixer 1. Solenoid impactor 25 can be activated to move from a retracted position to a position where it impacts valve housing 21 of dispensing unit 8 in the test position. To check the liquid level in container 4, solenoid impactor 26 is activated to impact valve housing 21. This causes valve housing 21 and the remainder of dispensing unit 8, including container 4, to vibrate and resonate. As a result, container 4 produces a vibration response with a frequency dependent on the liquid level. The vibration response is detected by a vibration sensor, such as microphone 27 or other type of acoustic sensor, which transmits a signal to data processing unit 28 for calculating the liquid level based on the detected vibration signal. If the liquid level is below a lower limit, a warning signal is generated and sent to the operator's user terminal. Microphone 27 can be located in any part of the interior of color mixer 1. Alternatively, the color matching machine may include more than one microphone or other vibration sensor.

[0050] Figure 3 An alternative embodiment of the dispensing unit 8' is shown, which includes an impact rod 29, one end 29A of which abuts against the container 4', while the opposite second end 29B is within reach of the solenoid impactor 26' when the dispensing unit 8' is in the test position. The adjacent end 29A is widened. The impact rod 29 extends between the container 4' and the piston pump 9, and when the dispensing unit 8' is in the test position, the second end 29B, which bends around the piston pump 9, is aligned with the solenoid impactor 26'. When the solenoid impactor 26' is activated, it strikes the second end 29B of the impact rod 29, and the impact rod 29 transmits the impact force to the container wall, causing the container 4' to vibrate. The vibration signal is detected by a microphone 27 and analyzed by a control unit.

[0051] Figure 4 The upper half of the graph shows the vibration signal of the resonant container 4. The lower half of the graph shows the Fourier transform of this acoustic signal. The maximum peak P1 represents the natural frequency of the resonant container. The higher the frequency of this peak, the more the container 4 is filled. The second peak P2 can be a characteristic of, for example, the density of the toner. Each toner has a characteristic density, so this information can be used to check whether the container has been refilled with the correct type of toner. Alternatively or additionally, the AI ​​module can be used to identify patterns in the vibration signal and / or its Fourier transform to analyze the amount of toner in the container, the type of toner, and / or the degree of degradation.

[0052] Figure 5An alternative embodiment of the dispensing unit 8 for the color mixing machine 1 of FIG. 1 is shown. In the illustrated embodiment, the color mixing machine 1 is provided with a flexible wall section 30 within the space 31 of the valve housing 21, which is in fluid communication with the internal space 15 of the container 4 when the valve 10 is in the withdrawn position, connecting the internal space 15 of the container 4 to the piston pump 9. The flexible wall 30 will expand and deform in response to hydraulic pressure applied by the liquid column in the container 4. The degree of deformation of the flexible wall section 30 is a parameter depending on the amount of liquid present in the container 4.

[0053] In an alternative embodiment, the flexible wall section includes a plate and a flexible sleeve that provides a sealing connection between the plate and the valve body. The flexible sleeve is configured to allow the plate to tilt in response to hydraulic pressure applied by a column of liquid in the container. The tilt angle of the plate can be measured, providing an indication of the amount of liquid present in the corresponding container 4.

[0054] The color mixing machine 1 also includes a sensor 32 for determining the degree of deformation or displacement of the flexible wall section 30. The sensor 32 has a fixed position, for example, mounted to the inner wall of the housing 2 or to a frame or other part of the color mixing machine 1 that is separate from the turntable 5. When the sensor 32 is held in the appropriate position, the individual dispensing units 8 can be moved by the turntable 5 and placed at a test position within the reach of the sensor 32.

[0055] Sensor 32 can be connected to a data processing unit (not shown) to calculate the amount of liquid in container 4 based on the sensed deformation or displacement of the flexible wall section 30. If the calculated liquid level in container 4 is below a threshold, the data processing unit can send an alarm to the operator.

[0056] Figure 6 A flexible wall section 41, formed as a separate component, is shown for sealing an opening 42 in the valve housing 43, such as Figure 7 As shown in the perspective cross-section. The flexible wall section 41 includes a peripheral circular sealing ring 44. The top side of the sealing ring 44 is a circular rigid flap 45, which has a hinge 46 hinged relative to the sealing ring 44 and is connected to the circular side surface 47 of the sealing ring 44 by a flexible foil 48 having harmonica-like folds. Due to the harmonica-like folds, the flexible foil 48 allows the rigid flap 45 to be hinged relative to the sealing ring 44, for example, in a... Figure 6 The flat position and the extended position shown are hinged.

[0057] exist Figure 7In this embodiment, the outer sealing ring 44 is attached in a sealing manner to the boundary of the opening 42 outside the container and secured by the clamping ring 49. In the illustrated embodiment, the flexible wall section 41 is covered by a protective cap 50 when not used to determine the liquid level in the container. The opening 42 communicates with an internal space 51 within the valve housing 43, which in turn communicates with the interior of the associated container (not shown). The valve housing 43 has a dispensing opening 52 and holds a valve body 53, which can rotate between a dispensing position (the container is closed and the dispensing opening 52 is open) and a withdrawal position (the dispensing opening 52 is closed and the container is open to allow liquid to be withdrawn from the container by an associated pump). In the withdrawal position, liquid from the container flows into the internal space of the valve housing 43. The hydraulic pressure applied by the liquid depends on the liquid level in the container. This hydraulic pressure forces the rigid flap 45 to hinge outwards. The hinge angle of the rigid flap 45 is a measure of the hydraulic pressure, which in turn is a measure of the liquid level in the container.

[0058] It should be noted that the accompanying drawings are schematic and not necessarily drawn to scale, and details not necessary for understanding the invention may have been omitted. Unless otherwise stated, the terms "upward," "downward," "below," "above," etc., refer to embodiments oriented as shown in the drawings. Furthermore, elements that are at least substantially the same or perform at least substantially the same function are represented by the same numbers.

Claims

1. A distributor (1), comprising: - Portable platform; - Multiple distribution units (8) located on the platform, each distribution unit including a container (4), a pump (9), and a valve (10); and - Vibration sensor (27); The characteristic feature is that the distributor further includes an impact element (26), and The platform is movable to position one of the plurality of allocation units (4) at the test location; When the distribution unit (8) is positioned at the test position, the distribution unit (8) is within the reach of the impact member (26).

2. The dispenser according to any one of the preceding claims, wherein, The vibration sensor (27) includes an acoustic sensor, such as a microphone.

3. The dispenser according to any one of the preceding claims, wherein, The impactor is a solenoid impactor (26).

4. The dispensing machine according to any one of the preceding claims, wherein, The dispenser is a color mixing machine (1) used for color mixing of paints. The movable platform is a turntable (5). The dispensing units are arranged in one or more circular arrays on the turntable, such that the pumps (9) with the corresponding valves (10) of the dispensing units (8) are arranged in a single outer circular array. The impactor has a fixed position, and rotating the turntable allows each distribution unit to move into the reach of the impactor.

5. The dispensing machine according to claim 4, wherein, The impactor is positioned adjacent to the peripheral section of the turntable and radially points toward the rotation axis of the turntable.

6. The dispenser according to claim 4 or 5, wherein, One or more of the plurality of dispensing units include an impact rod, one end of which is adjacent to the container (4) when the dispensing unit is in the test position, and the opposite second end is within reach of the impactor (26, 26').

7. A method for determining the quantity and / or mass of liquid in a selected container of a plurality of containers (4) of a dispenser (1), the method using a vibration sensor (27) and an impactor (26) configured to vibrate the selected container (4). in, The selected container of the plurality of containers is moved relative to the sensor and the impactor to a test position within the reach of the impactor (26); The impactor (26) is activated, and the vibration generated by the container is sensed by the sensors (27, 32).

8. The method according to claim 7, wherein, The sensor includes a vibration sensor, such as an acoustic sensor, and the signal is subsequently processed and analyzed, for example, by Fourier analysis and / or an AI module, to identify the inherent frequency and optionally additional frequency peaks.

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