JPH0138490B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an electric coffee brewer.

Conventional structure and its problems Conventionally, a fully automatic coffee boiler in which the coffee bean grinding function and the dripping function are integrated, and the coffee brewing function is automatically switched to the dripping function after grinding the coffee beans, is shown in Figure 1. A structure as shown in FIG. 3 is also known. That is, the coffee boiler having the configuration shown in FIG. 1 has a container 1 in which a coffee bean grinding chamber and a filtration chamber for extracting coffee liquid and separating the extract and residue are integrated. 1 is equipped with a cutter 3 that is rotationally driven by a drive motor 2, and a filter 4 that separates the extract from the residue at the bottom.After the coffee beans are ground by the cutter 3, they are stored in a water tank 5. The heated water is introduced into a water pipe 8 formed integrally with a heater 7 via a check valve 6, and the steam pressure generated by heating pushes up the hot water to a discharge pipe 8 located above the container 1. Coffee was obtained by pouring hot water into the container 1 from the discharge pipe 8'.

However, in this configuration, when the coffee beans are ground, the cutter 3 rotates at high speed and generates a large centrifugal force, so if a filter medium is placed on the peripheral wall of the container 1, this filter medium will quickly break. Therefore, as mentioned above, the filter medium,
That is, the filter 4 must be placed on the bottom surface of the container 1, which is relatively less susceptible to centrifugal force. In addition, regarding the material of the filter 4, the mesh-like filter 4 made of stainless steel wire is used because paper, which is normally used for coffee extraction, would be extremely damaged during grinding of coffee beans. be.

In general, in order to extract good quality coffee,
The conditions for crushing are appropriate particle size and a small amount of fine powder (particle size finer than 48 mesh).
Therefore, the condition for extraction is to complete the extraction in about 3 to 4 minutes at a high temperature of 92 to 96°C using hot water that has been boiled. In addition, 3
In order to complete the extraction in ~4 minutes, the filtration capacity of the filter medium must be sufficient, and the coffee powder must be sufficiently swollen by pouring hot water to form an appropriate filtration layer on the coffee powder itself. The key is to pour the hot water quietly and continuously without stirring the filter layer. On the other hand, pulverization with the above-described configuration results in a high-speed pulverization state in a closed space as shown in pulverization engineering, and generates an extremely large amount of fine powder. In addition, during extraction, the filtration area of the filter 4 is narrow, coffee powder clogs the filter 4 during grinding, and a large amount of fine powder fills the gaps between coffee particles, resulting in an extremely long filtration time. As a result, it usually took 7 to 12 minutes to brew 5 cups of coffee.

In addition, with the hot water supply system described above, a sufficient temperature increase cannot be expected, and the hot water supply and extraction temperature time characteristics are shown in FIG. Note that this second
In the figure, the curve A shows the hot water supply temperature, the curve B shows the extraction temperature, and the curve C shows the extraction time.

As described above, the coffee extracted by the coffee brewer shown in FIG. 1 was extremely tasteless and cloudy due to the inclusion of fine coffee powder.

The coffee boiler shown in Fig. 3 is constructed independently of a coffee bean grinding chamber 9 and a filtration chamber 10 for extracting coffee liquid and separating the extracted liquid and residue using a filter medium such as a paper filter. The coffee bean grinding chamber 9 houses a cutter 12 which is rotationally driven by a drive motor 11, and a part of the peripheral wall of the coffee bean grinding chamber 9 is provided with a porous portion 13 for discharging the ground coffee liquid. The porous section 13 and the filtration chamber 10 are communicated with each other through the transfer pipe 14. When coffee beans are ground to an appropriate particle size in the coffee bean grinding chamber 9, they are sequentially transferred from the porous section 13 to the filtration chamber 10. The coffee is discharged onto an internal filter medium 15, and once this discharge is completed, coffee is extracted using the same principle as the conventional example shown in FIG.

In the configuration shown in Figure 3 above, improvements can be seen in the generation of fine powder during pulverization and the filtration ability of the filter medium compared to the conventional example shown in Figure 1, but the same problems can be seen in the hot water supply temperature and extraction time during extraction. In addition to this, there are also extremely serious problems in terms of operability during use. Ordinary coffee beans contain a lot of oil and fat, and the ground coffee powder becomes sticky and easily adheres to the side wall of the coffee bean grinding chamber 9. Therefore, all the beans ground in the coffee bean grinding chamber 9 are transferred to the filtration chamber 10.
It is not discharged to the tank, but remains partially attached to the inner wall of the transfer pipe 14. In the next extraction, the generated steam enters the transfer pipe 14 and condenses, so that the adhering coffee powder does not easily come off, and is transferred while the coffee beans are being repeatedly ground and coffee is extracted. The pipe 14 would become clogged and the discharge function would stop. To solve this problem,
It is necessary to remove and clean the coffee bean grinding chamber 9 each time it is used, but in this case, it is troublesome to forget it, and there are many parts to be cleaned, so it is very time-consuming. Furthermore, the ground coffee powder is discharged at a high speed, so once the filtration chamber 1
Even if it is guided to the filter medium 15 arranged at 0, repulsion,
This has caused many problems, such as some of the coffee powder being scattered and entering the gap between the filter medium 15 and the filter chamber 10, resulting in the coffee powder being mixed into the extract when coffee is extracted.

Purpose of the Invention In view of the above-mentioned conventional problems, an object of the present invention is to provide an electric coffee boiler that can produce high-quality coffee with the original flavor of coffee and is extremely easy to use. shall be.

Structure of the Invention In order to achieve the above object, the present invention heats water in a tank in a heating section and circulates the water in the tank, and when the water temperature in the tank reaches boiling temperature due to the circulation, the water temperature is sensed. A thermally responsive member made of an actuated shape memory alloy switches hot water supply from the tank side to hot water supply to the filtration chamber side, and the thermally responsive member is placed inside the tank. According to this configuration, After the water temperature in the tank reaches a predetermined temperature, hot water is supplied to the filtration chamber side, making it possible to obtain high-quality coffee with a strong aroma and original coffee flavor.It is also made of a shape memory alloy. Because the heat-responsive member is placed inside the tank, the shape memory alloy must be cooled with water and immediately return to its original state when reused. Therefore, the waiting time for recovery is shortened. Without,
Since it can be reused immediately, it is very easy to use, and is also harmless in terms of food hygiene and exhibits high durability.

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below with reference to the accompanying drawings. 4 to 7, 21 is a crushing filter container, and this crushing filter 21 includes a substantially cylindrical raw material crushing chamber 24 containing a cutter 23 that is rotationally driven by a drive motor 22, and this raw material crushing chamber. A filtration chamber 25 for accommodating and extracting coffee beans ground in step 24 is integrally formed and arranged side by side, and the raw material grinding chamber 24 and the filtration chamber 25 are provided in a part of the peripheral wall of the raw material grinding chamber 24. It communicates via a porous portion 26. Further, the bottom portion 27 of the raw material crushing chamber 24 is formed in a mortar shape, and the porous portion 2
By arranging 6 so as to cut the circle drawn by the peripheral wall of the raw material grinding chamber 24, when grinding coffee beans,
As soon as the coffee beans are properly agitated and ground evenly and have a suitable particle size, they are immediately transferred to the filtration chamber 2.
5. In addition, the filtration chamber 25 is provided with a rib 28 having a substantially triangular cross section in an annular shape from a height that contacts the lower edge of the porous portion 26, so that when a paper filter medium 29 is provided, coffee powder that is crushed and discharged can be removed. This prevents the liquid from entering the gap between the filter medium 29 and the filter chamber 25. Furthermore, by providing a second filter 30 at the bottom of the filtration chamber 25, coffee powder entering through the gap between the filter medium 29 and the filtration chamber 25 is prevented from being mixed into the coffee liquid. In addition, as the filter medium, in addition to the paper filter medium 29,
A mesh filter medium 31 made of metal or resin can also be used.

32 is a lid of the crushing filter container 21, and this lid 32 has an inclined surface 3 on the part located above the raw material crushing chamber 24.
A dome-shaped protrusion 34 having a diameter of 3 is formed, and a hot water receiver 35 for dispersing hot water during hot water supply and a hole 36 for discharging steam are formed in a portion located above the filtration chamber 25. . Reference numeral 37 denotes a coffee brewer main body, and this coffee brewer main body 37 has a drive motor 22 on the left leg 38, controls the operating time of this drive motor 22, and turns on electricity from the drive motor 22 when the operation is finished, as will be described later. A timer device (time switch) 40 for switching to the heater 39 is housed, and the right leg portion 4
1 is formed with a tank 42 for storing water.
This tank 42 is connected to a water pipe 44 formed integrally with the heater 39 via a check valve 43 provided at the bottom. Further, the central portion of the coffee boiler main body 37 is a space for storing a coffee receiver 45, and an inclined surface 46 is formed on the upper bridge portion connecting the left and right legs 38, 41. This facilitates the attachment and detachment of the coffee receiver 45 and prevents the steam generated from the coffee accumulated in the coffee receiver 45 from condensing. In addition, the raw material crushing chamber 2
4 and a filtration chamber 25 integrally formed.
1 is detachably attached to the coffee boiler main body 37.

Reference numeral 47 denotes a tapping chamber formed in a dome shape from a transparent heat-resistant resin and for reducing the discharge steam pressure.The upper surface 48 of this tapping chamber 47 has a substantially cylindrical weight lower portion 49 and its outer peripheral portion. A steam discharge hole 50 is provided at the bottom surface 51, and a discharge port 5 is provided on the bottom surface 51 with one end open toward the top surface and the other end connected to the water pipe 44.
2 and a drain port 53 are provided. Also, the water outlet 53
Below, the filter chamber 25 is rotatably supported by the coffee boiler main body 37, and is always supported by a spring 54.
A hot water guide 55 is provided which is biased in the direction of , that is, in the direction of arrow A, and can selectively guide the hot water flowing out from the hot water outlet 53 to either the tank 42 or the filtration chamber 25 through the open end 61. can. Further, the hot water guide 55 is provided with a notch 56.

Reference numeral 57 denotes a thermally responsive member disposed near the bottom of the tank 42. This thermally responsive member 57 is made of a shape memory alloy, and when the water temperature in the tank 42 is low, it succumbs to the tension pressure of the bias spring 58 and becomes compressed. However, when the water temperature reaches the shape memory temperature, the shape memory alloy 57 expands and pushes down the rod 60 integrally formed with the hook 59 in the direction of arrow B. Note that this shape memory alloy 57 is made of a Ni-Ti alloy, has high rust resistance, and is harmless.
The hook 59 of the rod 60 is located where the open end 61 of the hot water guide 55 is located on the tank 42 side.
The hot water guide 55 is engaged with the notch 56 and is locked. Further, one end of the rod 60 protrudes, and by pushing this protrusion 62, the engagement between the hook 59 of the rod 60 and the notch 56 of the hot water guide 55 can be released at any time. 63 is a lid of the coffee boiler body 37, and this lid 63 serves to prevent dust and the like from entering the appliance body.

The operation of the above configuration will now be described.
First, open the lid 63 and open the open end 61 of the hot water guide 55.
After holding the coffee beans on the tank 42 side, open the lid 32 of the grinding filter 21, put the required amount of coffee beans into the raw material grinding chamber 24, and attach the filter medium 29 so as to tightly contact the side wall of the filter chamber 25. , tank 42
After supplying the required amount of water, the lids 32 and 63 are closed.
Next, after setting the time switch 40 to a predetermined time, when electricity is started, the drive motor 22 is activated and the coffee beans are ground. Then, the ground coffee beans are sequentially passed through the porous portion 26 into the filtration chamber 2.
5. When this discharge is completed, the drive motor 22 is stopped and the power supply to the heater 39 is switched. When this heater 39 is energized, the water pipe 44
The water filled in the tank is heated and eventually begins to boil locally. At this time, due to the boiling pressure of the water filled in the water pipe 44, a check valve 43 is installed on the tank 42 side.
Due to the presence of the hot water, the hot water is ejected through the discharge port 52 into the receiving chamber 47 without backflow, but the pressure of this ejection is weakened at the lower part 49 of the weight, and the hot water is separated into steam and hot water. 55 and is returned to the tank 42 again, and removes unnecessary components such as limescale along with steam through the steam exhaust hole 50.
discharge from. When this operation is continuously repeated, the water temperature in the tank 42 gradually rises. Initially, the temperature of the hot water spouted from the discharge port 52 is 80 to 90°C, but as the water temperature in the tank 42 rises, the temperature of the water spouted from the discharge port 52 increases.
The temperature of the water spewed out from 2 also rises, and eventually reaches a boiling state of nearly 100 degrees Celsius. By setting the water temperature in the tank 42 at this time to the memory temperature of the shape memory alloy 57, the shape memory alloy 57 expands against the force of the bias spring 58 and moves the rod 60 downward.
As a result, the hook 59 of the rod 60 and the hot water guide 5
As a result, the hot water guide 55 rotates, and its open end 61 is located above the filtration chamber 25. As a result, 100℃
The heated hot water is dispersed by the hot water receiver 34 and dripped onto the coffee grounds. In addition, in the early stage when hot water is circulating through the tank 42 and the water pipe 44, the water pipe 44
4 is an intermittent boiling, so low-temperature hot water is intermittently spouted from the discharge port 52, but when it reaches a continuous boiling state, an extremely large amount of hot water is continuously spouted from the discharge port 52. Pour out hot water at 100℃.
Therefore, a predetermined amount of hot water is continuously supplied to the filtration chamber 25.

FIG. 8a shows the discharge port 52 based on the operation described above.
Figure 8b shows the temperature of the hot water pumped out of the tank, the water temperature in the tank 42, and the extraction temperature in the filtration chamber 25 over time. This figure shows the change in temperature over time for each case.

When brewing coffee after circulating hot water, as shown in FIG.
By releasing the engagement between the hook 59 of 0 and the notch 26 of the hot water guide 55 and applying electricity in this state, coffee can be extracted in the conventional time.

Effects of the Invention As described above, according to the present invention, water in a tank is heated by a heating section and circulated in the tank, and when the water temperature in the tank reaches a predetermined temperature due to the circulation,
A heat-responsive member made of a shape memory alloy that senses the water temperature and switches the hot water supply from the tank to the filtration chamber allows for a high-quality coffee with a strong aroma and the original flavor of coffee. You can get high-quality coffee, and since a heat-responsive member made of shape memory alloy is placed inside the tank, the shape memory alloy is always cooled with water and immediately returns to its original state when reused. Therefore, there is no waiting time until return,
Since it can be reused immediately, it is very easy to use, and is also harmless in terms of food hygiene and exhibits high durability.

[Brief explanation of drawings]

Figure 1 is a side sectional view of a conventional fully automatic electric coffee brewer that integrates a coffee bean grinding chamber and a filtration chamber, and Figure 2 is a diagram of the coffee extraction temperature and time characteristics of the coffee brewer shown in Figure 1. , FIG. 3 is a side sectional view of a conventional fully automatic electric coffee brewer in which a coffee bean grinding chamber and a filtration chamber are arranged side by side, and FIG. 4 is a perspective view of an electric coffee brewer showing an embodiment of the present invention. Figure 5 is an exploded perspective view of the same coffee boiler, Figure 6 is a longitudinal sectional view of the same coffee boiler, Figure 7 is an enlarged sectional view of the main parts of the same coffee boiler, and Figure 8a. FIG. 8b is a diagram showing the coffee extraction temperature and time characteristics when the coffee brewer is operated in circulation, and FIG. 8b is a diagram showing the coffee extraction temperature and time characteristics when the coffee brewer is not circulating. 25...Filtering chamber, 37...Coffee boiler body, 39...Heater (heating part), 42...Tank,
43...Check valve, 44...Water pipe, 55...Hot water guide, 57...Shape memory alloy (thermal responsive member), 61
...The open end of the hot water guide.

Claims (1)

[Claims] 1 A tank provided in the main body and containing water, a heating section that heats the water in this tank, a filtration chamber that extracts coffee, and one end of which communicates with the bottom of the tank via a check valve, and A water pipe whose other end faces a hot water guide that freely moves between the tank and the filtration chamber, and a shape memory alloy that senses the water temperature and activates when the water temperature in the tank reaches a predetermined temperature through circulation. An electric coffee boiler comprising: a hot water supply device that operates a hot water guide to switch from supplying hot water to a tank side to supplying hot water to a filtration chamber side using a thermally responsive member, the thermally responsive member being disposed within the tank.