JP2005037073A - Hot water supply device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hot water supply device capable of reliably supplying hot water of consistent temperature and amount without increasing manufacturing cost. <P>SOLUTION: The hot water supply device 1 supplies hot water outside after heating supplied water, and comprises a boiler body 22 which stores the supplied water and supplies the stored hot water outside when hot water is supplied, a heater 23 to heat the water in the boiler body 22 by electricity, a boiler hot water temperature sensor 24 to detect the temperature of the water in the boiler body 22 as the first water temperature, and a heater control device which continuously operates the heater 23 when the detected first water temperature is not higher than the threshold temperature Tth, and operates the heater 23 at smaller electricity before the first water temperature reaches the target temperature Tu higher than the threshold temperature Tth after the first water temperature exceeds the threshold temperature Tth. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hot water supply apparatus, for example, a hot water supply apparatus that is applied to a cup-type vending machine, a beverage dispenser, and the like and supplies hot water used for cooking regular coffee or the like at an optimum temperature.

  Conventionally, the thing of patent document 1 is known as a hot-water supply apparatus applied to the vending machine. This hot water supply device is mainly provided in a vending machine that sells cup noodles, and is provided in a hot water tank for storing the supplied water and in the hot water tank, and heats the water in the hot water tank. A main heater, a sub-heater having a smaller amount of heat generation per operating time than the main heater, and a temperature sensor for detecting the water temperature in the hot water tank are provided.

  In this hot water supply apparatus, the water temperature in the hot water tank is controlled as follows. First, when the water temperature in the hot water tank is 91 ° C. or lower, the main heater is turned on to heat the water in the hot water tank. When the water temperature in the hot water tank becomes 94 ° C. or higher due to this heating, the main heater is turned off and the sub-heater is turned on to further heat the hot water in the hot water tank. And when the water temperature in a hot water tank becomes 97 degreeC or more, a sub heater is turned off. Thereafter, when the water temperature in the hot water tank decreases and reaches 94 ° C., the sub heater is turned on again. As described above, after the water temperature in the hot water tank reaches 94 ° C. or higher, the water temperature in the hot water tank is kept at approximately 94 to 97 ° C. by switching the sub heater ON / OFF.

  Thus, in the conventional hot water supply apparatus, the main heater is operated until the water temperature in the hot water tank reaches a certain high temperature (94 ° C.), and after that temperature is reached, only the sub-heater is switched on / off. Thus, the water temperature in the hot water tank is kept within a predetermined range. However, in this hot water supply apparatus, since the two heaters of the main heater and the sub heater are used for heating the water in the hot water tank, the manufacturing cost becomes higher than when a single heater is used.

  Further, the water temperature control in the hot water tank by switching the heater on / off as described above has the following problems. In other words, in order to save energy and space, a small hot water tank with a small capacity is used, and if the water temperature in such a hot water tank is controlled by switching the heater on / off, the water temperature will remain even after the heater is turned off. It may continue to rise for a while, and so-called overshoot may cause boiling in the hot water tank. When boiling occurs in the hot water tank, the supply amount of hot water tends to vary. Therefore, when the above hot water supply device is applied to, for example, a vending machine that sells regular coffee, the amount of hot water supplied to the raw material for cooking a cup of coffee varies from sale to sale, and the quality is stable. I can't sell coffee.

  Of course, in consideration of the overshoot of the water temperature in the hot water tank, the set temperature at which the heater is turned off so that the maximum temperature of the water temperature in the hot water tank is about 98 ° C., for example, so that boiling does not occur in the hot water tank. It is conceivable to lower the value. However, in this case, the set temperature at which the heater is turned on must also be lowered, so the difference between the maximum and minimum water temperatures in the hot water tank becomes large. In this case, regular coffee with stable quality cannot be sold.

  The present invention has been made to solve the above-described problems, and provides a hot water supply apparatus that can reliably supply a stable temperature and amount of hot water without increasing the manufacturing cost. Objective.

JP-A-8-185565 (Page 4, FIGS. 1, 2 and 5)

  A hot water supply apparatus according to claim 1 of the present invention is a hot water supply apparatus that supplies water to the outside after heating the supplied water, and stores the supplied water and supplies the stored water to the outside during hot water supply. A hot water tank, a heater that heats the water in the hot water tank by energization, a first water temperature sensor that detects the temperature of the water in the hot water tank as a first water temperature, and the detected first water temperature is a predetermined threshold. When the temperature is lower than the value, the heater is continuously operated, and the heater is operated with a smaller first energization amount until the predetermined target temperature higher than the threshold value is reached after the first water temperature exceeds the threshold value. And a heater control device.

  According to this configuration, the temperature of the water stored in the hot water tank (first water temperature) is detected by the first water temperature sensor, and the heater is continuously operated when the first water temperature is equal to or lower than the threshold value. Thereby, the temperature of the water in a hot water tank rises. Then, until the first water temperature exceeds the threshold value and reaches the target temperature, the heater is operated at a first energization amount that is smaller than the energization amount when the first water temperature is equal to or lower than the threshold value. Let As described above, since the heater is continuously operated until the first water temperature reaches the threshold value, the temperature of the water in the hot water tank can be rapidly increased to the threshold value. On the other hand, since the heater is operated with a small first energization amount until the target temperature is reached after the first water temperature exceeds the threshold value, the temperature of the water in the hot water tank is maintained at this first energization amount. Moreover, even if the heater is stopped when the first water temperature reaches the target temperature, the boiling of the hot water tank can be ensured by appropriately setting the hot water tank so that it does not boil due to overshoot after the heater stops. Can be prevented. Thereby, the stable temperature and quantity of hot water can be supplied reliably. Also, in the above configuration, unlike a conventional hot water supply apparatus that requires two heaters, the temperature of the water in the hot water tank can be raised with a single heater, and one heater can be omitted, which is manufactured compared to the conventional one. Cost can be reduced.

  The invention according to claim 2 of the present invention is characterized in that, in the hot water supply apparatus of claim 1, the first energization amount is set so as to gradually decrease as the first water temperature approaches the target temperature.

  According to this configuration, as the first water temperature approaches the target temperature, it is possible to raise the temperature of the water in the hot water tank while gradually decreasing the thermal energy given to the water in the hot water tank by the operation of the heater. Thus, the water in the hot water tank can be efficiently heated to the target temperature without consuming excess energy, and the boiling in the hot water tank can be more reliably prevented.

  According to a third aspect of the present invention, in the hot water supply apparatus according to the first or second aspect, the second water temperature sensor that detects the temperature of the water supplied to the hot water tank as the second water temperature, and the detected second water temperature. Accordingly, the apparatus further includes an energization amount correction unit that corrects the first energization amount.

  According to this configuration, the second water temperature sensor detects the temperature of the water supplied to the hot water tank (second water temperature), and reflects the second water temperature in the first energization amount. Can be corrected to an optimum value according to the installation environment temperature of the hot water supply apparatus. Therefore, by operating the heater with such a first energization amount, the water in the hot water tank can be heated more efficiently.

  According to a fourth aspect of the present invention, in the hot water supply apparatus according to any one of the first to third aspects, the heater control device operates the heater at a predetermined second energization amount after the first water temperature reaches the target temperature. It is characterized by making it.

  According to this configuration, after the first water temperature reaches the target temperature, the heater is operated at a predetermined second energization amount. Therefore, the second energization amount is appropriately set to such an extent that the water temperature in the hot water tank can be maintained. By setting, the water temperature in the hot water tank can be maintained near the target temperature.

  According to a fifth aspect of the present invention, in the hot water supply apparatus according to the fourth aspect, the heater control device stops the heater when the first water temperature exceeds the target temperature, and the first water temperature falls below the target temperature. The heater is operated with the second energization amount.

  According to this configuration, after the first water temperature once exceeds the target temperature and then falls below the target temperature, the heater is operated with the second energization amount. The operation can be started in a stable state where the water temperature in the tank is substantially the target temperature, that is, in a state where the temperature is not increased unless heat energy is supplied. Thus, since the heater operation is started by the second energization amount in a state where the water temperature in the hot water tank is stable, the subsequent water temperature control in the hot water tank can be stably performed.

  The invention according to claim 6 of the present invention is characterized in that, in the hot water supply apparatus according to any one of claims 1 to 5, the first and second energization amounts are set based on energization time to the heater. .

  According to this configuration, the first and second energization amounts of the heater can be controlled relatively easily by setting the energization amount to the heater based on the energization time.

It is a figure showing typically the hot-water supply device by one embodiment of the present invention. It is a flowchart which shows a boiler hot water temperature rise process. It is a flowchart which shows a boiler hot water temperature maintenance process. It is a time chart which shows the relationship between boiler hot water temperature and energization and a stop of a heater. It is a flowchart which shows the hot water supply process at the time of coffee sale.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, this hot water supply device 1 is built in a cup-type vending machine that sells regular coffee, and supplies hot water having an optimum temperature to the coffee extractor 2 according to the type of coffee to be extracted. To do. The hot water supply device 1 includes a water supply unit 3, a heating unit 4 for heating the water supplied from the water supply unit 3, and a control device (heater control device, energization amount correcting means) (not shown) including a microcomputer for controlling them. It has.

  The water supply section 3 is connected to a cistern 11 for storing tap water taken from the outside, and a pump that is connected to the cistern 11 via a water intake tube T1 and pumps water in the cistern 11 to a boiler 21 described later of the heating section 4. 12, a strainer 13 connected to the water intake tube T1 for filtering the water flowing out from the cistern 11, and connected between the strainer 13 of the water intake tube T1 and the pump 12 to measure the amount of water flowing from the cistern 11 to the pump 12. And a flow meter 14 to be used.

  The cistern 11 has a relatively small volume so that a predetermined amount (for example, 800 cc) or more of water is always stored. The cistern 11 is provided with a water temperature sensor 15 (second water temperature sensor). The water temperature sensor 15 detects the temperature of the water stored in the cistern 11 (second water temperature), and the detection result. Is input to the control device.

  The pump 12 is an electromagnetic water pump having a relief valve 12a, and at the time of sale, a predetermined amount (for example, 150 cc) of water required for cooking a cup of coffee is supplied to the heating unit 4 via the water supply tube T2. Is supplied to a boiler 21 described later. The pump 12 is configured to maintain the internal pressure of the boiler 21 so that the relief valve 12a is opened when the internal pressure exceeds a predetermined pressure (for example, 8 atm) higher than the atmospheric pressure. Is set. Note that a return tube T3 is connected to the relief valve 12a. When the relief valve 12a is opened, steam or hot water flowing out from the relief valve 12a is returned to the cistern 11 through the return tube T3. .

  The heating unit 4 includes a small boiler 21. The boiler 21 includes a boiler body 22 (hot water tank), a heater 23 that heats the water in the boiler body 22, and a boiler hot water temperature that detects the temperature (first water temperature) of the water (hot water) in the boiler body 22. And a sensor 24 (first water temperature sensor).

  The boiler body 22 is made of a metal plate such as a stainless steel plate, and is configured of a cylindrical sealed container having a predetermined capacity (for example, 300 cc) having pressure resistance (for example, 10 atm). In addition, the boiler body 22 is provided with an inflow portion 22a for allowing water from the water supply portion 3 to flow in, and an outflow portion 22b for allowing hot water to flow out when hot water is supplied to the coffee extractor 2. The inflow portion 22a is connected to the water supply tube T2, while the outflow portion 22b is connected to a hot water supply tube T4 having one end connected to the coffee extractor 2. A hot water supply valve 25 is provided in the middle of the hot water supply tube T4. The hot water supply valve 25 is an electromagnetic three-way valve having one inflow port and two outflow ports, and the end portions of the hot water supply tube T4 on the boiler 21 side and the coffee extractor 2 side are respectively inflow ports of the hot water supply valve 25. A pressurizing tube T5 having a pressurizing valve 26 at one end is connected to the other outflow port.

The pressurizing valve 26 is configured in the same manner as a general relief valve, and when the internal pressure of the boiler 21 exceeds a predetermined pressure (for example, gauge pressure: 1 kgf / cm ² (98 kPa)) larger than the atmospheric pressure. , Is set to open. Therefore, in the state where the hot water supply valve 25 is switched to the pressurizing valve 26 side, the internal pressure of the boiler 21 can be increased to the predetermined pressure. Further, in the pressurizing valve 26, the predetermined pressure at the time of opening is set to a value smaller than that of the relief valve 12a of the pump 12. Therefore, when the internal pressure of the boiler 21 exceeds the predetermined pressure, the pressurization valve 26 is opened, and steam or hot water flowing out from the pressurization valve 26 is collected in the drainage container 27. Even if the pressurization valve 26 is not opened due to a failure of the pressurization valve 26 or the like, the relief valve 12a of the pump 12 can be opened to prevent an overpressure state of the boiler 21.

  The heater 23 heats water in the boiler body 22 by energization from a power source (not shown), and is controlled by the control device. Moreover, the boiler hot water temperature sensor 24 detects the temperature of the hot water in the boiler main body 22, and the detection result is input into a control apparatus.

  Note that the boiler body 22 is provided with an airing prevention switch 28, and the airing prevention switch 28 prevents energization of the heater 23 when there is no water in the boiler body 22. ing. Further, the boiler body 22 is provided with a drain port 29 for closing the boiler body 22 to the drainage container 27 by closing the boiler body 22 at all times and opening the boiler body 22 during maintenance or the like. Yes.

  In the hot water supply device 1 configured as described above, the inflow portion 22 a side of the boiler 21 is normally sealed by the pump 12, while the outflow portion 22 b side is sealed by the hot water supply valve 25 and the pressurizing valve 26.

  Next, the operation of the hot water supply apparatus 1 configured as described above will be described with reference to FIGS. In the following description, first, the hot water temperature in the boiler 21 in the hot water supply device 1 (hereinafter referred to as “boiler hot water temperature BT”) control will be described, and then the hot water supply operation of the hot water supply device 1 at the time of selling regular coffee. explain. Further, it is assumed that a constant power is supplied to the heater 23 when the heater 23 described below is energized.

  FIG. 2 shows a process for increasing the boiler hot water temperature BT (boiler hot water temperature increasing process). In this process, for example, the power supply to the vending machine is interrupted for a long time at the beginning of installation of the vending machine. It is executed when it has been. In this process, first, in step 1 (illustrated as “S1”, the same applies hereinafter), it is determined whether or not the boiler water temperature BT is higher than a threshold temperature Tth (threshold value, for example, 80 ° C.). When the determination result is NO and the boiler hot water temperature BT is equal to or lower than the threshold temperature Tth, energization of the heater 23 is started (step 2), and the heater 23 is continuously operated.

  When the boiler hot water temperature BT rises by energizing the heater 23 and becomes higher than the threshold temperature Tth (step 3: YES), the heater 23 is operated at a predetermined first energization rate (first energization amount). (Step 4). The first energization rate in this case is determined by experiments or the like, and is set to gradually decrease, for example, stepwise or continuously as it approaches a set temperature Ts (eg, 97 ° C.) as a target temperature. In this embodiment, the energization rate immediately after the boiler hot water temperature BT exceeds the threshold temperature Tth is, for example, 16% (energization time: about 10 seconds / min), and the energization rate immediately before reaching the set temperature Ts is For example, it is set to 8% (energization time: about 5 seconds / minute).

  When the boiler hot water temperature BT exceeds the set temperature Ts (step 5: YES, FIG. 4: point A), the energization to the heater 23 is stopped (step 6). By stopping energization of the heater 23, the boiler hot water temperature BT once becomes higher than the set temperature Ts and then decreases. Then, when the boiler hot water temperature BT becomes equal to or lower than the set temperature Ts (step 7: YES, FIG. 4: point B), energization to the heater 23 is started (step 8). When a predetermined time (for example, 5 seconds) has elapsed after the start of energization of the heater 23 (step 9: YES), the energization of the heater 23 is stopped (step 10), and this process is terminated. By the above boiler water temperature rise processing, the boiler water temperature BT becomes substantially the set temperature Ts.

  After the completion of the above-described boiler hot water temperature rise process, the boiler hot water temperature holding process is executed so as to hold the boiler hot water temperature BT substantially at the set temperature Ts. In this process, the heater 23 is operated at a predetermined second energization rate (second energization amount). The second energization rate is determined by experiments or the like, similar to the first energization rate, and specifically, the heater 23 is controlled as follows. That is, in this process, first, in step 21 in FIG. 3, it is determined whether or not a predetermined time has elapsed after the energization of the heater 23 is stopped in step 10 in FIG. When the determination result is YES, energization to the heater 23 is started (step 22, FIG. 4: point C). Then, when a predetermined time (for example, 5 seconds) has elapsed after the start of energization of the heater 23 (step 23: YES), the energization of the heater 23 is stopped (step 24). By repeating these steps 21 to 24, the boiler hot water temperature BT is kept substantially at the set temperature Ts so as not to fall below the lower limit temperature Td (for example, 95 ° C.).

  In the present process, as described above, the second energization rate is determined by experiment or the like, and accordingly, the time from the energization stop of the heater 23 to the energization start, and from the energization start of the heater 23 to the energization stop. Time is determined.

  Next, with reference to FIG. 5, the hot water supply process at the time of coffee sale is demonstrated. In addition, at the time of sales standby, the boiler hot water temperature maintaining process is continuously executed, so that the boiler hot water temperature BT is maintained at approximately 97 to 95 ° C., and the boiler 21 is filled with hot water. It is assumed that the valve 25 is switched to the pressurizing valve 26 side. Further, it is assumed that a predetermined amount of coffee beans are supplied to the coffee extractor 2 before hot water supply according to the product selected by the purchaser.

  First, at the time of sale, it is determined whether or not so-called strong coffee, which is a strong regular coffee with a strong bitterness, has been selected (step 31). If the determination result is NO and a coffee other than strong coffee is selected, steps 32 to 34 described later are skipped, and hot water in the boiler 21 is supplied to the coffee extractor 2 (step 35). Specifically, the hot water supply valve 25 that has been switched to the pressurizing valve 26 side is switched to the coffee extractor 2 side, and the pump 12 is operated to generate a predetermined amount (for example, 150 cc) required for cooking a cup of coffee. The same amount of water as hot water is pumped from the cistern 11 to the boiler 21. Thereby, a predetermined amount of water is supplied to the boiler 21 through the water supply tube T2 and the inflow portion 22a, and the supplied hot water is supplied to the coffee extractor 2 through the outflow portion 22b and the hot water supply tube T4. Is done.

  Further, in this case, since the water temperature in the boiler 21 is lowered when the boiler 21 is supplied with water, a heater operation process for quickly increasing the water temperature is executed simultaneously with the hot water supply (step 36), and the hot water supply process Exit. In this heater operation process, for example, heat energy required to raise a predetermined amount of water supplied to the boiler 21 to the water temperature in the boiler 21 before water supply can be imparted to the hot water in the boiler 21. Then, the heater 23 is operated.

  When the determination result in step 31 is YES, that is, when strong coffee is selected by the purchaser, energization of the heater 23 is started (step 32). In this case, since the boiler 21 is in a sealed state, when the hot water in the boiler 21 is heated by the heater 23, the internal pressure of the boiler 21 rises above the atmospheric pressure, and accordingly the boiling point of the hot water also rises. . As a result, the boiler hot water temperature BT becomes higher than 100 ° C.

  Next, it is determined whether or not the boiler hot water temperature BT has reached a predetermined temperature (for example, 105 ° C.) higher than 100 ° C. (step 33). And when boiler hot water temperature BT becomes more than predetermined temperature (step 33: YES), electricity supply to heater 23 is stopped (step 34), and the case where coffee other than the strong coffee mentioned above is selected. A predetermined amount of hot water is supplied to the coffee extractor 2 (step 35), a heater operation process is executed (step 36), and the hot water supply process is terminated.

  In this case, immediately after the hot water supply valve 25 is switched to the coffee extractor 2 side, the hot water supplied to the coffee extractor 2 is supplied in a steam state until the pressure drops to atmospheric pressure. As a result, the coffee beans in the coffee extractor 2 can be steamed with steam, and even higher quality coffee can be cooked (extracted). In addition, the latent heat of the steam can warm the space between the hot water supply valve 25 of the hot water supply tube T4 and the coffee extractor 2, thereby suppressing the heat energy taken away by the hot water supply tube T4 and the like. Can be supplied to the coffee extractor 2 to obtain high-quality regular coffee (strong coffee).

  As described above in detail, according to the hot water supply apparatus 1 of the present embodiment, the heater 23 is continuously operated until the boiler hot water temperature BT reaches the threshold temperature Tth. Can be raised quickly. On the other hand, from the time when the boiler hot water temperature BT exceeds the threshold temperature Tth until the temperature reaches the set temperature Ts, the heater 23 is turned on at the first energization rate set so as to gradually decrease as the boiler hot water temperature BT approaches the set temperature Ts. Since it operates, the hot water in the boiler 21 can be efficiently heated to the set temperature Ts without causing boiling in the boiler 21.

  Further, after the boiler hot water temperature BT reaches the set temperature Ts, the heater 23 is operated at the second energization rate, and the operation is performed after the boiler hot water temperature BT exceeds the set temperature Ts once. Since it starts at a lower timing, the boiler hot water temperature BT can be stably held in the vicinity of the set temperature Ts, and a stable temperature and amount of hot water can be reliably supplied to the coffee extractor 2 during hot water supply. be able to. In addition, hot water having a temperature exceeding 100 ° C. can be reliably supplied as required.

  In addition, this invention can be implemented in various aspects, without being limited to the said embodiment described. In the embodiment, the case where the hot water supply apparatus 1 of the present invention is applied to a cup type vending machine has been described. However, the present invention is not limited to this, and can be applied to a beverage dispenser. It can be applied to various devices that require

  Further, in the embodiment, when the heater 23 is energized, constant power is supplied to the heater 23 and the heater 23 is operated based on the energization rate that is the energization time per unit time. The amount of power to be supplied to the heater 23 may be changed so that the overall energization amount is the same as when the heater 23 is operated based on the energization rate. Good. In this case, energization to the heater 23 and ON / OFF switching at the time of stopping can be greatly reduced, and the life of the heater 23 can be prolonged.

  Furthermore, you may make it correct | amend the 1st electricity supply rate which should operate the heater 23, and the 2nd electricity supply rate according to the water temperature in the cistern 11. Since the water temperature in the systern 11 is affected by the installation environment temperature of the vending machine, the water temperature is optimally adapted to the installation environment temperature of the vending machine by reflecting the water temperature in the first and second energization rates. Can achieve a high current-carrying rate. And the hot water in the boiler 21 can be heated more efficiently by operating the heater 23 at such an energization rate.

  The detailed configuration of the hot water supply device 1 shown in the embodiment is merely an example, and can be appropriately changed within the scope of the gist of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hot-water supply apparatus 2 Coffee extractor 3 Water supply part 4 Heating part 15 Water temperature sensor (2nd water temperature sensor)
21 Boiler 22 Boiler body (hot water tank)
23 heater 24 boiler hot water temperature sensor (first water temperature sensor)
25 Hot water supply valve Tth threshold temperature (threshold)
Tu upper limit temperature (target temperature)
BT boiler hot water temperature

Claims (6)

A hot water supply device that heats the supplied water and supplies it to the outside,
A hot water tank for storing the supplied water and supplying the stored water to the outside during hot water supply;
A heater that heats the water in the hot water tank by energization;
A first water temperature sensor that detects a temperature of water in the hot water tank as a first water temperature;
When the detected first water temperature is equal to or lower than a predetermined threshold, the heater is continuously operated, and after the first water temperature exceeds the threshold, a predetermined higher than the threshold is reached. A heater control device that operates the heater with a smaller first energization amount until a target temperature is reached;
A hot water supply apparatus comprising:   The hot water supply apparatus according to claim 1, wherein the first energization amount is set so as to gradually decrease as the first water temperature approaches the target temperature. A second water temperature sensor for detecting a temperature of water supplied to the hot water tank as a second water temperature;
The hot water supply apparatus according to claim 1, further comprising an energization amount correction unit that corrects the first energization amount according to the detected second water temperature.   The hot water supply device according to any one of claims 1 to 3, wherein the heater control device operates the heater with a predetermined second energization amount after the first water temperature reaches the target temperature.   The heater control device stops the heater when the first water temperature exceeds the target temperature, and operates the heater at the second energization amount after the first water temperature falls below the target temperature. The hot water supply apparatus according to claim 4.   The hot water supply apparatus according to any one of claims 1 to 5, wherein the first and second energization amounts are set based on energization time to the heater.

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