Drinking water equipment and its control methods

Abstract

This invention relates to the field of drinking water equipment technology, specifically providing a drinking water device and its control method. The aim is to solve the problem of inaccurate outlet water temperature caused by inconsistencies in the overall load, pump, structural components, and piping of existing drinking water devices, which result in discrepancies between the actual and target water flow rates. To this end, the drinking water device of this invention includes a water circuit in which a pump and an instant heater are connected in series along the water flow direction. The control method includes: acquiring the target outlet water temperature and inlet water temperature and determining a target temperature rise value accordingly; determining the target water flow rate based on the target temperature rise value and the actual heating power of the instant heater; determining the target voltage of the outlet pump based on the target water flow rate and the correspondence between the pump voltage and water flow rate; controlling the pump to operate at the target voltage, controlling the instant heater to operate, and acquiring the outlet water temperature of the water circuit; comparing the outlet water temperature with the target outlet water temperature, and selectively correcting the correspondence between voltage and water flow rate based on the comparison result.

Description

Technical Field

[0001] This invention relates to the field of drinking water equipment technology, specifically providing a drinking water equipment and its control method. Background Technology

[0002] With the continuous improvement of people's living standards, water dispensers, water purifiers, and other drinking water equipment have become common household appliances. These devices are equipped with instant heaters (such as quartz tubes or thick-film rapid heating elements). Room temperature water, driven by a water pump, flows through the instant heater and is rapidly heated into hot water before being discharged. Since the heating power of the instant heater is fixed, to achieve different outlet water temperatures, the flow rate of water passing through the instant heater is usually adjusted by regulating the water pump speed, which in turn is achieved by regulating the pump's voltage.

[0003] However, in the overall system design, due to cost and system considerations, water flow sensors are generally omitted. The controller of the whole machine stores the correspondence between water pump voltage and water pump flow rate. When controlling the water pump to drive the water flow to the instant heater, the input voltage of the water pump is determined according to the target water flow rate and the correspondence between water pump voltage and water flow rate. The corresponding voltage is then input to the water pump so that the water flow through the instant heater reaches the target water flow rate. However, due to the inconsistency of the overall load, water pump, structural components, and pipelines of different drinking water equipment in actual production, the flow rate of water flowing through the instant heater of different drinking water equipment may differ when the water pump is working under the same input voltage. This leads to a deviation between the outlet water temperature and the set outlet water temperature.

[0004] Therefore, a new technical solution is needed in this field to solve the above problems. Summary of the Invention

[0005] The present invention aims to solve the above-mentioned technical problems, namely, to solve the problem of inaccurate water temperature caused by the inconsistency between the actual water flow rate and the target water flow rate due to the inconsistency of the overall load, water pump, structural components, and pipelines of existing drinking water equipment.

[0006] In a first aspect, the present invention provides a control method for a drinking water device, the drinking water device including a water circuit, wherein a water pump and an instant heater are connected in series along the water flow direction in the water circuit, the control method including: acquiring a target outlet water temperature and an inlet water temperature of the instant heater; determining a target temperature rise value based on the inlet water temperature and the target outlet water temperature; determining a target water flow rate based on the target temperature rise value and the actual heating power of the instant heater; determining a target voltage of the water pump based on the target water flow rate and the correspondence between the voltage of the water pump and the water flow rate; controlling the water pump to operate at the target voltage, controlling the instant heater to operate, and acquiring the outlet water temperature of the water circuit; comparing the outlet water temperature with the target outlet water temperature, and selectively correcting the correspondence between the voltage and the water flow rate based on the comparison result.

[0007] In the preferred embodiment of the above control method, the step of "comparing the outlet water temperature with the target outlet water temperature and selectively correcting the correspondence between the voltage and the water flow rate based on the comparison result" specifically includes: if the outlet water temperature and the target outlet water temperature do not meet the set relationship, then the correspondence between the voltage and the water flow rate is corrected.

[0008] In the preferred embodiment of the above control method, the step of "comparing the outlet water temperature with the target outlet water temperature and selectively correcting the correspondence between voltage and water flow rate based on the comparison result" specifically includes: if the outlet water temperature and the target outlet water temperature satisfy the set relationship, then the correspondence between voltage and water flow rate is not corrected.

[0009] In the preferred embodiment of the above control method, the setting relationship is: the outlet water temperature is equal to the target outlet water temperature.

[0010] In the preferred embodiment of the above control method, the set relationship is: the difference between the outlet water temperature and the target outlet water temperature is less than a preset difference.

[0011] In the preferred embodiment of the above control method, the step of "correcting the correspondence between the voltage and the water flow rate" specifically includes: adjusting the voltage of the water pump and obtaining the outlet water temperature of the water circuit; when the outlet water temperature of the water circuit and the target outlet water temperature meet the set relationship, stopping the adjustment of the water pump voltage; obtaining the current input voltage and current actual heating power of the instantaneous heater; and calculating the equivalent heating power under standard conditions according to the following formula: P 标 =P 测 (220 / U 测 ) 2 , where P 标 P is the equivalent heating power. 测 U represents the current actual heating power of the instantaneous heater.测 The current input voltage of the instantaneous heater is used; the current water flow rate of the water circuit is calculated based on the difference between the outlet water temperature and the inlet water temperature and the equivalent heating power; the theoretical water flow rate corresponding to the current voltage of the water pump is determined based on the current voltage of the water pump and the correspondence between the voltage and water flow rate of the water pump; the flow rate difference between the current water flow rate of the water circuit and the theoretical water flow rate is calculated; the updated correspondence between the voltage and water flow rate of the water pump is obtained by adding the flow rate difference to all the water flow rates in the correspondence between the voltage and water flow rate of the water pump.

[0012] In a preferred embodiment of the above control method, the control method includes: obtaining multiple updated correspondences between the voltage and water flow rate of the water pump according to the above steps based on multiple different target outlet water temperatures; and fitting a curve representing the correspondence between the voltage and water flow rate of the water pump based on the curves represented by the multiple updated correspondences between the voltage and water flow rate of the water pump.

[0013] In the preferred embodiment of the above control method, the control method is performed during the factory testing phase of the drinking water equipment.

[0014] In a preferred embodiment of the above control method, the drinking water device is equipped with a power detection element for detecting the heating power of the instant heater and a voltage detection element for detecting the input voltage of the instant heater. The control method is executed when the drinking water device is used for the first time, or at a set frequency during use, or when a user's instruction is received.

[0015] When adopting the above technical solution, the target temperature rise is determined based on the target outlet water temperature and the inlet water temperature of the instant heater. The target water flow rate is determined based on the target temperature rise and the actual heating power of the instant heater. The target voltage of the water pump is determined based on the target water flow rate and the correspondence between the pump voltage and the water flow rate. Then, the water pump is controlled to work under the target voltage, the instant heater is controlled to work, and the outlet water temperature of the water circuit is obtained. The outlet water temperature is compared with the target outlet water temperature, and the correspondence between the voltage and the water flow rate is selectively corrected based on the comparison result.

[0016] Through such control, the relationship between the pump voltage and water flow can be corrected when the outlet water temperature is inaccurate. This allows the water dispenser to determine the target voltage of the pump based on the target water flow and the relationship between the pump voltage and water flow. When the pump operates at the target voltage, the water flow driven by it can reduce or even eliminate the deviation between the outlet water temperature and the target outlet water temperature, making the outlet water temperature more accurate.

[0017] In a second aspect, the present invention provides a drinking water device comprising: a memory; a processor; and a computer program, the computer program being stored in the memory and configured to be executed by the processor to implement the control method of the drinking water device as described in any of the above technical solutions.

[0018] It should be noted that the drinking water equipment has all the technical effects of the control method of the drinking water equipment described in any of the above technical solutions, and will not be repeated here. Attached Figure Description

[0019] The preferred embodiments of the present invention are described below with reference to the accompanying drawings, in which:

[0020] Figure 1 This is a diagram showing the main steps of the control method for the drinking water equipment of the present invention;

[0021] Figure 2 This is a detailed step diagram of the control method for the drinking water equipment of the present invention;

[0022] Figure 3 This is a diagram illustrating the specific steps of "correcting the correspondence between voltage and water flow" in the control method of the drinking water equipment of this invention. Detailed Implementation

[0023] First, those skilled in the art should understand that the embodiments described below are merely for explaining the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0024] It should be noted that in the description of this invention, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; and it can also refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0026] Based on the problem mentioned in the background art that the inconsistency between the actual water flow rate and the target water flow rate caused by the inconsistency of the overall load, water pump, structural components, and pipelines of existing drinking water equipment leads to inaccurate water temperature, this invention provides a control method for drinking water equipment. The water flow rate driven by the water pump when it runs according to the target voltage can reduce or even eliminate the deviation between the water temperature and the target water temperature, making the water temperature more accurate.

[0027] The following is combined with Figures 1 to 3 The present invention will now be described. Among other things, Figure 1 This is a diagram showing the main steps of the control method for the drinking water equipment of the present invention; Figure 2 This is a detailed step diagram of the control method for the drinking water equipment of the present invention; Figure 3 This is a diagram illustrating the specific steps of "correcting the correspondence between voltage and water flow" in the control method of the drinking water equipment of this invention.

[0028] The drinking water device of the present invention includes a water circuit, in which a water pump and an instant heater are connected in series along the water flow direction. Figure 1 As shown, the control method of the drinking water device of the present invention mainly includes the following steps:

[0029] Step S100: Obtain the target outlet water temperature and the inlet water temperature of the instantaneous heater.

[0030] It should be noted that the target outlet water temperature can be a preset outlet water temperature in the controller of the water dispenser, or a target outlet water temperature input by the user. A first temperature sensor is installed on the upstream pipeline of the instant heater, which is used to detect the inlet water temperature of the instant heater.

[0031] Step S200: Determine the target temperature rise value based on the inlet water temperature and the target outlet water temperature.

[0032] Specifically, the difference between the target outlet water temperature and the inlet water temperature is the target temperature rise value.

[0033] Step S300: Determine the target water flow rate based on the target temperature rise value and the actual heating power of the instantaneous heater.

[0034] Specifically, the instant heater is powered on, and its actual heating power is obtained by detecting the heating power of the instant heater through a power detection element. Alternatively, the actual heating power can be calculated by detecting the current input voltage of the instant heater and its resistance. The target water flow rate is calculated using the formula F = P / (C*ΔT), where F is the water flow rate, P is the heating power, C is the specific heat capacity of water, and ΔT is the temperature rise. Substituting the target temperature rise and the actual heating power of the instant heater into the formula F = P / (C*ΔT) yields the target water flow rate.

[0035] Step S400: Determine the target voltage of the water pump based on the target water flow rate and the correspondence between the pump voltage and the water flow rate.

[0036] Specifically, the relationship between the pump's voltage and water flow rate can be a one-to-one correspondence between multiple discrete voltage values ​​and multiple discrete water flow rates, or it can be a one-to-one correspondence between a series of continuous voltage values ​​and a series of continuous water flow rates. Based on the target water flow rate, the voltage corresponding to the target water flow rate is found from the relationship between the pump's voltage and water flow rate; this is the target voltage of the pump.

[0037] Step S500: Control the water pump to operate at the target voltage, control the instant heater to operate, and obtain the outlet water temperature of the water circuit.

[0038] Specifically, a second temperature sensor is installed on the downstream pipeline of the instantaneous heater, which is used to detect the outlet water temperature of the water circuit.

[0039] Step S600: Compare the outlet water temperature with the target outlet water temperature, and selectively correct the correspondence between voltage and water flow rate based on the comparison results.

[0040] Through such control, the relationship between the pump voltage and water flow can be corrected when the outlet water temperature is inaccurate. This allows the water dispenser to determine the target voltage of the pump based on the target water flow and the relationship between the pump voltage and water flow. When the pump operates at the target voltage, the water flow driven by it can reduce or even eliminate the deviation between the outlet water temperature and the target outlet water temperature, making the outlet water temperature more accurate.

[0041] like Figure 2 As shown, the control method for the drinking water equipment includes the following steps:

[0042] Step S100: Obtain the target outlet water temperature and the inlet water temperature of the instantaneous heater.

[0043] Step S200: Determine the target temperature rise value based on the inlet water temperature and the target outlet water temperature.

[0044] Step S300: Determine the target water flow rate based on the target temperature rise value and the actual heating power of the instantaneous heater.

[0045] Step S400: Determine the target voltage of the water pump based on the target water flow rate and the correspondence between the pump voltage and the water flow rate.

[0046] Step S500: Control the water pump to operate at the target voltage, control the instant heater to operate, and obtain the outlet water temperature of the water circuit.

[0047] Step S610: Determine whether the outlet water temperature and the target outlet water temperature meet the set relationship. If not, proceed to step S620.

[0048] Step S620: Correct the correspondence between voltage and water flow rate.

[0049] For example, the relationship is set so that the outlet water temperature is equal to the target outlet water temperature. That is, if the outlet water temperature is not equal to the target outlet water temperature, the voltage-water flow rate relationship is adjusted. If the outlet water temperature is equal to the target outlet water temperature, the voltage-water flow rate relationship is not adjusted.

[0050] like Figure 3 As shown, step S620 specifically includes:

[0051] Step S621: Adjust the voltage of the water pump and obtain the outlet water temperature of the water circuit.

[0052] Step S622: When the outlet water temperature of the water circuit meets the set relationship with the target outlet water temperature, stop adjusting the voltage of the water pump.

[0053] Step S623: Obtain the current input voltage and current actual heating power of the instant heater.

[0054] Specifically, the current input voltage of the instant heater can be detected by a voltage detection element, the current actual heating power of the instant heater can be detected by a power detection element, and the current actual heating power of the instant heater can also be calculated based on the current input voltage and resistance of the instant heater.

[0055] Step S624: Calculate the equivalent heating power under standard conditions using the following formula:

[0056] P 标 =P 测 (220 / U 测 ) 2 ,

[0057] Among them, P 标 For equivalent heating power, P 测 U represents the current actual heating power of the instantaneous heater. 测 This is the current input voltage of the instant heater.

[0058] Step S625: Calculate the current water flow rate of the water circuit based on the difference between the outlet water temperature and the inlet water temperature and the equivalent heating power.

[0059] Specifically, the current water flow rate can be calculated using the formula F = P / (C * ΔT). Here, F is the water flow rate, P is the heating power, C is the specific heat capacity of water, and ΔT is the temperature rise (the difference between the outlet and inlet water temperatures).

[0060] Step S626: Determine the theoretical water flow rate corresponding to the current voltage of the water pump based on the current voltage of the water pump and the correspondence between the voltage of the water pump and the water flow rate.

[0061] Based on the current voltage of the water pump, find the water flow rate corresponding to the current voltage of the water pump from the correspondence between the voltage and the water flow rate of the water pump, that is, the theoretical water flow rate corresponding to the current voltage of the water pump.

[0062] Step S627: Calculate the difference between the current water flow rate and the theoretical water flow rate of the waterway.

[0063] Specifically, the difference between the current water flow rate and the theoretical water flow rate is the flow rate difference. This difference is positive when the current water flow rate is greater than the theoretical water flow rate, and negative when the current water flow rate is less than the theoretical water flow rate.

[0064] Step S628: Add the flow difference to all water flow rates in the correspondence between the voltage and water flow rate of the water pump to obtain the updated correspondence between the voltage and water flow rate.

[0065] Because mains voltage fluctuates, the heating power of the instantaneous heater will vary under different voltages. When the water pump voltage is adjusted to ensure the outlet water temperature matches the target outlet water temperature, the water pump voltage adjustment is stopped. The current input voltage and actual heating power of the instantaneous heater are then obtained, and the result is calculated according to formula P. 标 =P 测 (220 / U 测 ) 2 The equivalent heating power under standard conditions is calculated. Based on the difference between the outlet and inlet water temperatures and the equivalent heating power, the current water flow rate of the water circuit is calculated, resulting in a more accurate current water flow rate. Then, based on the current pump voltage and the correlation between pump voltage and water flow rate, the theoretical water flow rate corresponding to the current pump voltage is determined. The flow rate difference between the current and theoretical water flow rates is calculated, and all water flow rates in the correlation between pump voltage and water flow rate are added to the flow rate difference to obtain a more accurate corrected correlation between voltage and water flow rate. After determining the target voltage of the pump based on the corrected correlation, the pump operates at the target voltage and drives the water flow rate to eliminate the deviation between the outlet water temperature and the target outlet water temperature, resulting in a more accurate outlet water temperature.

[0066] In another feasible embodiment, unlike the control method described above, the relationship is set such that the difference between the outlet water temperature and the target outlet water temperature is less than a preset difference (such as 0.5℃, 0.8℃, 1℃, or other suitable temperature values). This setting avoids the frequent correction of the pump's voltage and flow rate relationship even when the difference between the outlet water temperature and the target outlet water temperature is very small (i.e., the outlet water temperature is very close to the target outlet water temperature), thus preventing frequent correction operations and ensuring the accuracy of the outlet water temperature.

[0067] Preferably, the control method of the drinking water device of the present invention includes: obtaining a plurality of updated correspondences between the voltage and water flow of multiple water pumps according to the above steps based on a plurality of different target outlet water temperatures; and fitting a curve representing the correspondence between the voltage and water flow of the water pumps based on the curves represented by the multiple updated correspondences between the voltage and water flow of the water pumps.

[0068] By using this setting, compared to the correction method that obtains an updated voltage-water flow correspondence based on a flow difference, the impact of errors from a single flow difference can be further reduced, thus obtaining a more accurate voltage-water flow correspondence that is more compatible with the structure of the drinking water equipment.

[0069] In one specific embodiment, the control method for the water dispenser is executed during the factory testing phase. The main control board of the water dispenser is connected to a power testing device via its communication port, and the host computer communicates with both the power testing device and the water dispenser. The power testing device is used to detect the heating power of the instant heater in the water dispenser.

[0070] With this setting, during the factory testing phase of the water dispenser, the relationship between the pump voltage and water flow rate can be corrected if the water temperature deviates significantly from the target water temperature due to a mismatch between the pump voltage and water flow rate and the water dispenser itself. This ensures that the water temperature dispensed by the water dispenser is more accurate during user operation.

[0071] In another specific embodiment, the water drinking device is equipped with a power detection element for detecting the heating power of the instant heater and a voltage detection element for detecting the input voltage of the instant heater. The control method of the water drinking device is executed when the water drinking device is used for the first time, or executed at a set frequency during use, or executed when a user's instruction is received.

[0072] For example, when a user first gets hot water after purchasing the water dispenser, the main control board (i.e., the controller) runs a program corresponding to the control method of this invention. If the outlet water temperature does not meet the set relationship with the target temperature, the program corrects the relationship between voltage and water flow. During this correction process, the outlet water temperature also meets the set relationship with the target temperature, ensuring that the outlet water temperature meets the requirements. Furthermore, the next time the user gets hot water, the outlet water temperature will directly meet the requirements, optimizing the user experience.

[0073] For example, after purchasing a water dispenser, the user executes the above control method at a set frequency. This means that every set interval, the system checks whether the voltage-to-water flow rate correlation needs correction, and adjusts it accordingly when necessary. This setup prevents scale and other impurities from accumulating on the pipes during long-term use, which could cause discrepancies between the actual water flow rate and the flow rate determined by the voltage-to-water flow rate correlation, leading to inaccurate water temperature. This ensures the accuracy of the water temperature throughout the long-term use of the dispenser.

[0074] For example, after purchasing and using the water dispenser, if the user feels that the water temperature is inconsistent with the set temperature, they can input a detection and correction command. Upon receiving the user's detection and correction command, the water dispenser will execute the aforementioned control method to correct the voltage-water flow rate relationship when necessary.

[0075] On the other hand, the present invention also provides a drinking water device, the controller of which includes a memory; a processor; and a computer program, the computer program being stored in the memory and configured to be executed by the processor as the control method of the drinking water device in any of the above embodiments.

[0076] It should be noted that the memory in the above embodiments includes, but is not limited to, random access memory, flash memory, read-only memory, programmable read-only memory, volatile memory, non-volatile memory, serial memory, parallel memory, or registers, etc., and the processor includes, but is not limited to, CPLD / FPGA, DSP, ARM processor, MIPS processor, etc. Furthermore, the water drinking device can be a water purifier, water dispenser, or other suitable water drinking device.

[0077] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will all fall within the scope of protection of the present invention.

Claims

1. A control method for a drinking water device, characterized in that, The drinking water equipment includes a water circuit, in which a water pump and an instant heater are connected in series along the water flow direction. The control method includes: Obtain the target outlet water temperature and the inlet water temperature of the instantaneous heater; The target temperature rise value is determined based on the inlet water temperature and the target outlet water temperature. The target water flow rate is determined based on the target temperature rise and the actual heating power of the instantaneous heater. The target voltage of the water pump is determined based on the target water flow rate and the correspondence between the pump voltage and the water flow rate. The water pump is controlled to operate at the target voltage, the instantaneous heater is controlled to operate, and the outlet water temperature of the water circuit is obtained; The outlet water temperature is compared with the target outlet water temperature, and the correspondence between the voltage and water flow rate is selectively corrected based on the comparison result. The step of "comparing the outlet water temperature with the target outlet water temperature and selectively correcting the correspondence between the voltage and water flow rate based on the comparison result" specifically includes: If the outlet water temperature does not meet the set relationship with the target outlet water temperature, then the correspondence between the voltage and the water flow rate is corrected. The steps for "correcting the correspondence between voltage and water flow rate" specifically include: Adjust the voltage of the water pump and obtain the outlet water temperature of the water circuit; When the outlet water temperature of the water circuit meets the set relationship with the target outlet water temperature, the voltage adjustment of the water pump is stopped; Obtain the current input voltage and current actual heating power of the instantaneous heater; The equivalent heating power under standard conditions is calculated using the following formula: Q 标 =P 测 (220 / U 测 ) 2 , Among them, P 标 P is the equivalent heating power. 测 U represents the current actual heating power of the instantaneous heater. 测 The current input voltage of the instantaneous heater; The current water flow rate of the water circuit is calculated based on the difference between the outlet water temperature and the inlet water temperature and the equivalent heating power. The theoretical water flow rate corresponding to the current voltage of the water pump is determined based on the current voltage of the water pump and the correspondence between the voltage and the water flow rate of the water pump. Calculate the difference between the current water flow rate and the theoretical water flow rate of the waterway; The updated relationship between the voltage and flow rate of the water pump is obtained by adding the flow rate difference to all the water flow rates in the relationship between the voltage and flow rate of the water pump.

2. The control method according to claim 1, characterized in that, The step of "comparing the outlet water temperature with the target outlet water temperature and selectively correcting the correspondence between the voltage and water flow rate based on the comparison result" specifically includes: If the outlet water temperature and the target outlet water temperature satisfy the set relationship, then the correspondence between the voltage and the water flow rate will not be corrected.

3. The control method according to claim 1, characterized in that, The defined relationship is as follows: The outlet water temperature is equal to the target outlet water temperature.

4. The control method according to claim 1, characterized in that, The defined relationship is as follows: The difference between the outlet water temperature and the target outlet water temperature is less than a preset difference.

5. The control method according to claim 1, characterized in that, The control method includes: Based on multiple different target outlet water temperatures, the above steps are followed to obtain multiple updated correspondences between the voltage and water flow rate of the water pump; A curve representing the relationship between the voltage and water flow rate of the water pump is fitted based on the curves representing the correspondence between the voltage and water flow rate of the water pump in multiple updated versions.

6. The control method according to any one of claims 1 to 4, characterized in that, The control method is implemented during the factory testing phase of the drinking water equipment.

7. The control method according to any one of claims 1 to 4, characterized in that, The drinking water equipment is equipped with a power detection element for detecting the heating power of the instant heater and a voltage detection element for detecting the input voltage of the instant heater. The control method is executed when the water drinking equipment is used for the first time, or at a set frequency during use, or when a user's instruction is received.

8. A drinking water device, characterized in that, include: Memory; processor; as well as A computer program, stored in the memory and configured to be executed by the processor to implement the control method of the drinking water device according to any one of claims 1 to 7.

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