阅读说明：本技术 具有用于调节水温度的改进系统的浓缩咖啡机以及用于调节浓缩咖啡机中的水温度的方法 (Espresso coffee machine with improved system for regulating the temperature of the water and method for regulating the temperature of the water in an espresso coffee machine ) 是由 A·迪奥尼西奥 G·萨尔维 于 2018-03-20 设计创作，主要内容包括：本申请涉及一种浓缩咖啡机,该机器包括：分配组和相应咖啡锅炉,该咖啡锅炉在压力下容纳水；加热器装置,用于加热咖啡锅炉中的水；温度传感器,用于测量咖啡锅炉中的水的温度；处理器,该处理器与所述温度传感器连接,并设置成驱动所述加热器装置,以使得咖啡锅炉中的所述水处于设定的参考温度；其中,所述处理器包括反馈系统；以及所述设定参考温度的值根据以下参数中的至少一个而变化：(a)第一参数,该第一参数是从机器操作循环经过的时间或在一个时间间隔内机器的使用频率的函数；(b)第二参数,该第二参数是机器的部件温度的函数；以及(c)第三参数,该第三参数是环境的函数。(The present application relates to an espresso coffee machine comprising: a dispensing group and a respective coffee boiler containing water under pressure; a heater device for heating water in the coffee boiler; a temperature sensor for measuring a temperature of water in the coffee boiler; a processor connected to the temperature sensor and arranged to drive the heater means such that the water in the coffee boiler is at a set reference temperature; wherein the processor comprises a feedback system; and the value of the set reference temperature varies according to at least one of the following parameters: (a) a first parameter that is a function of elapsed time from a machine operation cycle or frequency of use of the machine over a time interval; (b) a second parameter that is a function of a temperature of a component of the machine; and (c) a third parameter, the third parameter being a function of the environment.)

1. A machine (10) for preparing and dispensing espresso coffee, comprising:

a water supply source (1);

a dispensing group (9) and a respective coffee boiler (4) containing water under pressure;

heating means (6) for heating the water in the coffee boiler (4);

a temperature sensor (7) for measuring the temperature of the water in the coffee boiler (4);

a processor (8) connected to the temperature sensor (7) and arranged to drive the heater arrangement (6) such that the water in the coffee boiler is at a set reference temperature (Trif, Trif _ new),

wherein the processor comprises a feedback system (PID); and

the value of the set reference temperature (Trif, Trif _ new) varies according to a first parameter which is a function of the time elapsed from the machine operating cycle or of the frequency of use of the machine within a time interval.

2. The machine (10) for preparing and dispensing espresso coffee according to claim 1, wherein: the processor is arranged to control the heater means (6) to be switched on or off in dependence on the temperature sensed by the temperature sensor (7).

3. The machine (10) for preparing and dispensing espresso coffee according to claim 1 or 2, wherein: the heater means (6) comprises an electrical resistance.

4. The machine (10) for preparing and dispensing espresso coffee according to claim 1, 2 or 3, wherein: the feedback system includes a proportional-integral-derivative or proportional-integral-derivative controller (PID).

5. The machine (10) for preparing and dispensing espresso coffee according to any one of the preceding claims, wherein: the first parameter is a function of the time elapsed from the last machine operation cycle.

6. Machine (10) for preparing and dispensing espresso coffee according to claim 5, wherein: said first parameter for varying said set reference temperature (Trif, Trif _ new) is the time elapsed from the last beverage extraction cycle, when the last dispensing operation is referred to as t₀When, the Trif can be varied as follows:

t₀<t₁：Trif_new＝Trif+ΔΤ1；

t₁<t₀<t₂：Trif_new＝Trif+ΔT2；

t₂<t₀<t₃：Trif_new＝Trif+ΔT3；

...

t_n-1<t₀<t_n：Trif_new＝Trif+ΔTn；

wherein:

t₁<t₂<...<t_nis the time of day or the like,

Δ T1, Δ T2.. Δ Tn is temperature (positive, negative, or zero),

wherein n is 1, 2, 3.

7. The machine (10) for preparing and dispensing espresso coffee according to any one of the preceding claims, wherein: the value of said set reference temperature (Trif, Trif _ new) is also varied as a function of a second parameter which is a function of the temperature of a machine part in contact with the water flow from the coffee boiler during the beverage dispensing operation.

8. The machine (10) for preparing and dispensing espresso coffee according to any one of the preceding claims, wherein: the value of said set reference temperature (Trif, Trif _ new) also varies as a function of a third parameter which is a function of the temperature of the environment in which the machine is installed.

9. A method of preparing and dispensing espresso, comprising:

supplying water (1) to a coffee boiler (4) containing water under pressure;

providing an allocation group (9);

heating (6) the water in the coffee boiler (4);

measuring the temperature of the water in the coffee boiler (4);

controlling the heating of water in a coffee boiler such that said water in the coffee boiler (4) is at a set reference temperature (Trif, Trif _ new);

providing a feedback system (PID); and

-changing said value of said set reference temperature (Trif, Trif _ new) according to a first parameter which is a function of the time elapsed from the machine operation cycle or the frequency of use of the machine within a time interval.

10. The method of claim 9, wherein: the first parameter is a function of the time elapsed from the last machine operation cycle.

11. The method of claim 9 or 10, wherein: said first parameter for varying said set reference temperature (Trif, Trif _ new) is the time elapsed from the last beverage extraction cycle, when the time of the last dispensing operation is referred to as t₀When, the Trif can be varied as follows:

t₀<t₁：Trif_new＝Trif+ΔΤ1；

t₁<t₀<t₂：Trif_new＝Trif+ΔT2；

t₂<t₀<t₃：Trif_new＝Trif+ΔT3；

...

t_n-1<t₀<t_n：Trif_new＝Trif+ΔTn；

wherein:

t₁<t₂<...<t_nis the time of day or the like,

Δ T1, Δ T2.. Δ Tn is temperature (positive, negative, or zero),

wherein n is 1, 2, 3.

12. The method of claim 9, wherein: the value of said set reference temperature (Trif, Trif _ new) is also varied as a function of a second parameter which is a function of the temperature of a machine part in contact with the water flow coming from the coffee boiler during a dispensing operation.

Technical Field

The present invention relates generally to the field of machines for preparing beverages. More particularly, the present invention relates to a machine for preparing espresso coffee (or another beverage) provided with an improved system for regulating the temperature of the water in the boiler. The invention also relates to a method for adjusting the temperature of water in an espresso coffee machine.

Background

EP2490580 relates to a machine for preparing coffee and the like. The machine comprises one or more operating groups, each comprising at least one boiler, a pump, a heating unit and a unit for extracting aroma and dispensing espresso coffee infusion through an associated duct. Each group is provided with a system for controlling and adjusting the production parameters of the espresso coffee. According to one embodiment, the machine comprises means for adjusting the extraction pressure of the espresso coffee infusion. According to one embodiment, the machine comprises means for adjusting the extraction temperature of the espresso coffee infusion. According to one embodiment, the machine comprises a control unit containing various stored pressure profiles that can be recalled by an operator.

The water required for the infusion of coffee is usually heated by direct or indirect contact of this water with a heating element, usually an electric resistance.

In an attempt to ensure a sufficiently stable water temperature, espresso coffee machines using a closed-loop regulating system are known. The system comprises a water container (reservoir), a heating element (e.g. a resistor, etc.), a temperature sensor and a regulating device.

The regulating device causes the heating element to be switched on or off depending on the temperature sensed by the temperature sensor. In particular, the adjustment means causes the heating element to be switched on when the temperature of the sensor is lower than a reference temperature (desired temperature), and otherwise causes the heating element to be switched off.

WO2017009186 and WO2017009189 of the present applicant describe lever or piston machines.

EP2789276 describes a modular machine.

Disclosure of Invention

The applicant has noticed that the temperature regulation systems employed in the known machines do not guarantee sufficient precision. In particular, the applicant has noted that the accuracy of the system may be negatively affected by the frequency of use of the machine and/or by other factors, such as the structure of the machine and/or environmental factors.

The applicant has also noticed that the water, along its flow path (from the moment it heats up until the moment it reaches the disk (puck) of coffee powder), comes into contact with a metallic (or non-metallic) component to which it gives off heat or from which it receives heat in some cases.

The applicant has also noticed that the temperature of the water reaching the coffee powder disc may be affected by the temperature of the room in which the machine is installed.

The applicant has also noticed that the frequency of use of the machine significantly affects the temperature of the water reaching the ground coffee disk. In other words, when the machine is used substantially continuously, the temperature of the water reaching the coffee powder disk is substantially constant and predictable, but in other use cases the temperature varies greatly. It is well known that espresso machines often have peak periods, periods of frequent use, but also periods of inactivity or sporadic use, which are not completely predictable. For example, after overnight inactivity, the first coffee dispensed in the morning is typically dispensed at a temperature below the desired temperature.

In any case, the temperature of the water in contact with the coffee powder differs from the reference temperature sensed by the temperature sensor for at least some of the reasons described above.

The applicant has aimed at providing a machine for preparing espresso coffee (or other beverages) which provides hot water so that it reaches the disk of coffee powder at a predetermined temperature (regardless of the frequency of use of the machine, the flow path of the water and the contact with the various components and/or environmental factors), so as to obtain a high repeatability and quality uniformity when dispensing the beverage.

According to a first aspect, the present invention relates to a machine for preparing and dispensing espresso coffee, comprising:

a water supply source;

a dispensing group and a respective coffee boiler containing water under pressure;

a heater device for heating water in the coffee boiler;

a temperature sensor for measuring a temperature of water in the coffee boiler;

a processor connected to said temperature sensor and arranged to drive said heater means such that said water in the coffee boiler is at a set reference temperature Trif, Trif _ new;

wherein the processor comprises a feedback system; and

the value of the set reference temperature varies according to at least one of the following parameters:

(a) a first parameter that is a function of elapsed time from a machine operation cycle or frequency of use of the machine over a time interval;

(b) a second parameter that is a function of a temperature of a component of the machine; and

(c) a third parameter that is a function of an environment in which the machine is installed.

Preferably, the processor is arranged to control the heater means to be switched on or off based on the temperature sensed by the temperature sensor.

The heater means may comprise a resistor.

The feedback system may comprise a proportional-integral-derivative or proportional-integral-derivative controller.

The first parameter may be a function of the time elapsed from the last machine operation cycle.

When the first parameter for changing said set reference temperature (Trif, Trif _ new) is the time elapsed from the last beverage extraction cycle and the time elapsed from the last dispensing operation is referred to as t₀Then, the Trif may be varied as follows:

t₀<t₁：Trif_new＝Trif+ΔΤ1；

t₁<t₀<t₂：Trif_new＝Trif+ΔT2；

t₂<t₀<t₃：Trif_new＝Trif+ΔT3；

…

t_n-1<t₀<t_n：Trif_new＝Trif+ΔTn；

wherein:

t₁<t₂<...<t_nis the time of day or the like,

Δ T1, Δ T2.. Δ Tn is temperature (positive, negative, or zero),

wherein n is 1, 2, 3.

Preferably, the second parameter may be a function of the temperature of a machine part in contact with the water flow from the coffee boiler during a beverage dispensing operation.

The third parameter may be a function of a temperature of an environment in which the machine is installed.

According to another aspect, the present invention provides a method of preparing and dispensing espresso, comprising:

water supplied in a coffee boiler, the coffee boiler containing water under pressure;

providing an allocation group;

heating water in a coffee boiler;

measuring the temperature of the water in the coffee boiler;

controlling heating of water in a coffee boiler such that the water in the coffee boiler is at a set reference temperature;

providing a feedback system; and

changing the value of the reference temperature according to at least one of the following parameters:

(a) a first parameter that is a function of elapsed time from a machine operation cycle or frequency of use of the machine over a time interval;

(b) a second parameter that is a function of a temperature of a component of the machine; and

(c) a third parameter that is a function of an environment in which the machine is installed.

Drawings

The invention will be more fully understood from reading the following detailed description (provided by way of non-limiting example) with reference to the accompanying drawings, in which:

figure 1 is a simplified hydraulic diagram showing only the main elements for understanding the invention;

figure 2 is a graph of a first temperature versus time; and

FIG. 3 is another graph of temperature versus time.

Detailed Description

Fig. 1 is a simplified hydraulic diagram. In particular, the hydraulic diagram in fig. 1 shows only a few components of the espresso coffee machine, i.e. the components that are necessary for understanding the present invention.

For convenience, the following description refers in particular to espresso coffee machines, but the invention is not limited to such machines and can be used in machines for dispensing other beverages. For example, barley flour or other cereal flour may be used instead of coffee flour. Therefore, the expression "espresso coffee machine" must be understood to also include machines for preparing other beverages. Similarly, the expression "espresso" must be understood to have a broad meaning, corresponding to the products used for preparing the beverage (coffee, barley or other cereals).

The machine to which the invention relates may also be a lever or piston type machine. As a further alternative, the invention can also be applied to machines of the modular type, for example of the type described in EP 2789276.

Typically, the espresso machine 10 receives water from a tank or pipe 1 and sends this cold water under pressure to downstream components by means of a pump 2. In other embodiments, the pump 2 is not present, since in any case a pressure sufficient for the correct operation of the machine (generally coming from the mains water supply) is guaranteed. For example, the pressure may be about 3 bar.

Downstream of the pump 2 there may be a solenoid valve 3 and a coffee boiler 4. The water is heated inside the coffee boiler 4 to a reference temperature, hereinafter indicated as Trif.

A group 9 for dispensing beverages (espresso coffee, etc.) is in fluid connection with the coffee boiler 4. In some machines, two or more distribution groups 9 are connected to the same coffee boiler. Each distribution group 9 is provided so that the portafilter (also called filter holder) 5 can be attached in a detachable manner. Again, each portafilter 5 comprises a body, generally substantially cylindrical, having a closed bottom provided with one or more nozzles 51. The body of the portafilter 5 is arranged to support a filter 52, which filter 52 is at least partially filled with pressed coffee powder 53.

For preparing espresso coffee, hot water under pressure contained in the coffee boiler 4 is made to pass through the coffee powder 53, seep out of the filter 52 and flow out of the nozzle 51.

The machine 10 preferably also comprises a substantially closed box-like body and a support surface with an associated drip tray for resting cups or other containers when dispensing the beverage.

Fig. 1 also shows, in schematic form, a processor 8(CPU, etc.) for managing certain electrical and/or electronic functions of the machine. Preferably, the processor 8 is mounted on the electronic board. For the purposes of the present invention, the term "processor" includes not only a CPU or the like, but also other electrical and/or electronic components, such as one or more memories (preferably non-volatile memories), relays, connectors, or the like.

For the purpose of the present invention, the processor 8 is connected to a temperature sensor 7, which temperature sensor 7 is arranged to sense the temperature of the water inside the coffee boiler. The processor 8 is also connected to a heating element for heating the water inside the coffee boiler. The heating element may typically comprise an electrical resistance. Obviously, the connection between the processor 8 and the heating element may be a physical connection (e.g. via a cable), but is preferably an indirect or logical connection. For example, the processor 8 can control the turning on or off of a heating element (e.g., a resistor) by operating a relay or the like.

As noted above, the processor may also manage other important functions of the machine, however, these functions are not relevant to the purposes of the present invention. Based on the drawing shown in fig. 1, the processor may be connected to the pump 2 and/or the solenoid valve 3.

The connections in the view of fig. 1 are shown as physical cable connections, but may also be wireless connections using any data transmission standard for Wireless Personal Area Networks (WPANs), such as Bluetooth, Zigbee, etc. In any case, a cable connection is preferred.

Typically, the processor 8 is arranged to maintain a certain suitable reference temperature within the coffee boiler. The processor controls the heating element to be turned on or off based on the temperature sensed by the temperature sensor. In particular, the processor 8 causes the heating element to be switched on when the temperature of the sensor is lower than a reference temperature (desired temperature), otherwise the processor 8 causes the heating element to be switched off.

Preferably, to improve thermal stability, the processor 8 does not only perform a comparison between the reference temperature and the temperature sensed by the temperature sensor 7, but also uses a more complex logic system. Preferably, according to the invention, the processor 8 uses a so-called proportional-integral-derivative or proportional-integral-derivative (PID) controller system. As is well known, PID systems are feedback systems commonly used in control systems. Due to the input determining the current value, the system is able to react to any positive or negative error tending towards a value of 0. The reaction to errors can be adjusted, which makes the system very versatile. Basically, the PID technique also takes into account the differentiation and integration of the temperature difference.

According to the invention, the reference temperature Trif is not constant but varies according to at least one of:

(a) a first parameter representative of the frequency of use of the machine and/or of the time elapsed from the reference extraction cycle;

(b) a second parameter representative of the temperature of a machine component, preferably of a component acted on by the water flow during preparation and/or dispensing of the beverage; and

(c) a third environmental parameter representing an environment in which the machine is installed.

With respect to parameter (a), the applicant has perceived that the temperature of the water dispensed and therefore the temperature of the beverage is particularly affected by the frequency of use of the espresso coffee machine and/or the time elapsed from the extraction cycle as a reference cycle. Preferably, the last (or penultimate) coffee dispensing operation performed by the machine can be taken as a reference extraction cycle.

According to the applicant, the use of machines with a varying frequency (many or a few coffees per hour) will cause the water to release different amounts of heat. This means that the water reaching the coffee powder has a different temperature depending on the use.

According to the invention, the processor 8 is arranged to modify the reference temperature Trif of the water inside the boiler suitably over time in order to compensate for the temperature drop due to the infrequent use of the machine. In other words, when a large drop in water temperature is expected, the Trif will increase accordingly. On the other hand, when only a slight temperature drop is expected, the Trif will increase less than in the former case. When the machine is operating under normal conditions and is used with a certain continuity, then the Trif will not increase, i.e., remain the same.

For example, when considering that the time elapsed since the last beverage extraction cycle is an important parameter for modifying the reference temperature Trif, and the time since the last dispensing operation is referred to as t0, the Trif may be modified as follows:

t₀<t₁：Trif_new＝Trif+ΔΤ1；

t₁<t₀<t₂：Trif_new＝Trif+ΔT2；

t₂<t₀<t₃：Trif_new＝Trif+ΔT3；

…

t_n-1<t₀<t_n：Trif_new＝Trif+ΔTn；

wherein the content of the first and second substances,

t₁<t₂<...<t_nis the time of day or the like,

Δ T1, Δ T2.. Δ Tn is temperature (positive, negative, or zero),

wherein n is 1, 2, 3. Typically n may be between 2 and 4.

For example, when:

t₀<at 30s, Trif _ new +0 deg.C

30s<t₀<At 60s, Trif _ new +1 deg.C

60s<t₀<At 90s, Trif _ new +2 deg.C

t₀>At 90s, Trif _ new +3 deg.C

Obviously, once the usage frequency of the rule is re-established, the Trif _ new will be Trif _ new +0 ℃ even after a long time of deactivation (e.g. Trif increases by 3 ℃).

In addition or as an alternative to the above criteria (based on the time elapsed from the last dispensing operation), the processor of the temperature regulation system may be arranged to modify the reference temperature Trif based on the number of extraction cycles in a certain time interval. The time interval may be a few seconds or minutes, for example 1, 5 or 10 minutes.

According to the invention, when the number of extraction cycles in the period is less than a predetermined threshold, it may be necessary to increase the temperature of the water in the coffee boiler, thus increasing the Trif. Thus, the processor 8 acts to increase the temperature of the heater arrangement accordingly.

The processor does not increase the temperature Trif when the number of extraction cycles is equal to the set value or within a set time interval of the extraction cycles.

In some cases, the processor may act to turn off the power supply to the resistor when the temperature inside the coffee boiler is too high (for some reason).

As mentioned above, in addition to or as an alternative to the above-mentioned criterion of the variation of the Trif, the reference temperature Trif may be varied according to a second parameter indicative of the temperature of a machine component, preferably a component acted on by the water flow during the dispensing of the beverage.

In other words, the processor of the system for adjusting the temperature of the water inside the coffee boiler can also be controlled by the temperature information of one or more components of the espresso coffee machine (including the dispensing group).

For example, the processor may be configured to receive temperature information associated with a solenoid valve, fitting, tube, connector, portafilter, filter basket that houses it, or other component through which water flows out of the boiler and to the filter. In this way, the processor acts to increase the temperature Trif based on the temperature of one or more components, which in turn indicates a drop in temperature that will affect the flow of water from the boiler to the distribution group. Therefore, when the temperature of the predetermined part is lower than a certain value, it may be necessary to increase the temperature of the water inside the coffee boiler. Thus, the processor acts to increase the temperature of the heater arrangement in a corresponding manner.

It is clear that apart from situations where it is necessary to increase the temperature in response to a non-optimal temperature of a particular component in the machine, situations may arise where the temperature of the component is within a particular optimal temperature range or (conversely) too high. In these cases, the processor operates accordingly.

As mentioned above, the reference temperature may be varied in accordance with a third environmental parameter indicative of the environment in which the machine is installed, in addition to or as an alternative to the above-mentioned Trif variation criterion (considered alone or in combination).

The environmental information may include, for example, the ambient temperature, the outside temperature, the atmospheric pressure, or the humidity of the room in which the machine is installed. For example, when the temperature inside the room in which the machine is installed is lower than a certain value, the temperature Trif may need to be increased.

Fig. 2 is a graph showing the change in water temperature with time. It can be seen that the temperature is regulated to a value in the range of the set reference temperature (Trif) due to the action of the regulation system according to the invention, comprising a PID or similar type of feedback system. The shape of the graph is purely qualitative in nature.

Fig. 3 is also a graph showing the change in water temperature with time. The graph in fig. 3 qualitatively represents the change in the Trif for one or more of the above criteria (a), (b) and/or (c). As can be seen from fig. 3, the temperature is regulated to a value in the set reference temperature (Trif) range or in the new set temperature Trif _ new range due to the action of the regulation system according to the invention, comprising a PID or similar type of feedback system.