JPH0157479B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating device for metal service plates such as steak plates and grill plates.

When cooking and serving steaks, other meats, and other roasted or grilled dishes in hotels, restaurants, etc., the ingredients are first cooked over an open flame, in the oven, or on a griddle, and then the food is cooked to prevent it from getting cold during the meal. out of consideration, in advance
The method is to serve the food on a high heat capacity metal tableware heated to around 200 degrees Celsius, such as a cast iron steak plate or grill plate. Conventionally, these metal service plates have been heated using a gas range or an oven, but especially when it is necessary to heat a large number of plates at once, equipment suitable for the throughput is required. be. In this case, when fuel gas is used for heating, a large amount of combustion gas is generated, which wastes a large amount of heat and deteriorates the working environment in the kitchen. Therefore, it becomes necessary to strengthen the ancillary equipment for ventilation and cooling of the cooking area. On the other hand, this type of heating of a plate involves what is called empty cooking of the plate.
Misaligned heating and cooking of dishes not only prevents effective service but also sometimes creates a fire hazard. Furthermore, since ovens that use electric heating use indirect heating, it takes a long time to heat up. For this reason, all conventional methods have problems.

The present invention has been made to solve the above-mentioned problems in heating metal service plates.

It is easy to think that induction heating could be used as a means to solve the above-mentioned problems in heating metal service plates. That is, as shown in FIG. 1, an excitation winding 2 is wound around a C-shaped core 10 formed by laminating, for example, silicon steel plates with low core loss and high magnetic permeability. If you place a metal material W, for example a plate material, between them and turn on the power source _E0 , an eddy current will be induced in the metal material W by the magnetic flux.
The metal material W generates heat due to the eddy current loss. Moreover, the energy conversion efficiency in this case is extremely high. Therefore, I think it would be a good idea to replace the metal material W with a metal plate. However, even if such a known induction heating method for metal materials is used as is for heating metal service plates, it alone cannot provide an effective solution. The present invention is characterized in that it solves the following problems peculiar to the heating of metal service plates by induction heating.

(1) In the case of metal service plates, it is not necessary to heat the entire plate, and the heating pattern only needs to be almost the same as the flat surface on which the food is served. The gap between the opposing end surfaces, which is the space for inserting the plate, may be set by considering only the thickness of the serving surface.

(2) However, since the plate has a rim, when considering insertion and removal into the gap between the opposing end faces, the workability will be poor unless the height of the rim is taken into consideration and the space is made quite wide.

(3) However, if the gap between the end faces is widened, the excitation current increases, which increases the KVA capacity, resulting in poor power factor due to insufficient current capacity and increased copper loss.

(4) Furthermore, when a commercial frequency power source is used, the electromagnetic force caused by the alternating magnetic field causes the plate to vibrate and generate noise.

The present invention will be explained according to the embodiment shown in FIGS. 2 and 3. Reference numeral 1 denotes a C-shaped iron core, which consists of U-shaped members 1a and 1b made of, for example, known laminated silicon steel plates, arranged to face each other. Parts 1a and 1
As shown in FIG. 2b, one of the opposing end surfaces of b, for example located on the right side in FIG. For example, a pin 13 made of a material having a much lower magnetic permeability than a silicon steel plate is inserted into the hole 12 and is rotatably connected. It is preferable that each engagement surface of the engagement portion 11 be coated with a coating layer made of a wear-resistant insulating material, or that a wear-resistant non-magnetic metal thin plate material be attached. 2a and 2b
is an excitation winding wound a predetermined number of times around each of the arm portions 14a and 14b of the C-type iron core 1;
Connect the wires so that magnetic flux is generated in the same direction within the wires. E is a commercial frequency power supply. 15a and 15
b is an end surface portion that bends downward and upward as one unit from the left end in each of the drawings of the arm portions 14a and 14b, and
The end face shape of 6b is formed to approximately match the shape of the flat serving surface of the metal service plate pl. For example, arm portion 14 among arm portions 14a and 14b
b is fixed, but the arm portion 14a is movable and, for example, is pinned by the spring force of a tension spring (not shown) having a spring constant sufficient to lift the arm portion 14a and end surface portion 15a upward against gravity. It is possible to rotate it around 13 and position it, for example, in the position shown in FIG. 2c. In this state, the end surface 16b of the end surface portion 15b and the end surface 16a of the end surface portion 15a are
The gap between the two is sufficiently larger than the thickness including the height of the edge of the metal service plate PL. An arc-shaped presser 32, which is fixed as one body to the tip of a rod 31 of the cylinder 3 disposed at a predetermined upper position, is in contact with approximately the center of the upper surface of the end surface portion 15a. The pressing force of the cylinder 3 is set to be sufficiently larger than the above-mentioned tension spring force and to be sufficient to suppress vibrations of the metal service plate pl caused by electromagnetic force when energized. Also, as shown in FIG. 2c, even when the rod 31 of the cylinder 3 is retracted to the maximum, the arm 14a
is sufficiently upwardly displaced by the tension spring, and the end face 1
The upper surface of 5a is in contact with the pressing force of the pressing member 32 while receiving the pressing force therefrom. A predetermined number of protrusions 17a, 17b are fixed to each of the end faces 16a, 16b. The protrusions 17a and 17b are preferably made of a hard heat-resistant material such as titanium.

In such a configuration, a case where a metal service plate pl is heated according to the present invention will be described as an example.
It is assumed that the rod 31 of the cylinder 3 is retracted to the maximum. Therefore, the movable arm portion 14a of the C-type core 1
is in a position displaced upward by the spring force of a tension spring (not shown), and the presser 32 is in contact with its upper surface, and the end surface 16a of the end surface portion 15a and the end surface 16b of the end surface portion 15b of the fixed arm portion 14b are in contact with the upper surface thereof. The gap is much larger than the wall thickness including the edge of the metal service plate PL. In this state, insert the metal service plate pl between the end faces 16a and 16b, and
The bottom surface of the plate is placed on the protrusion 17b at a position where the serving surface coincides with the end surface 16b. Then cylinder 3
is driven to move the rod 31 forward. Thereby, the presser 32 is fixed to the tip of the rod 31.
As a result, the end surface portion 15a is pressed against the spring force of the tension spring, and the movable arm portion 14a rotates about the pin 13 of the meshing portion 11 toward the fixed arm portion 14b. Along with this, the end surface 16a of the end surface portion 15a approaches the end surface 16b, and as the displacement further progresses, the end surface 16a approaches the end surface 16b.
The protrusion 17a on the end surface 16a contacts the upper surface of the metal service plate pl placed on the protrusion 17b on the plate 6a, and is firmly pressed by the pressing force of the cylinder 3. In such a state, the commercial frequency power supply E
When the C-type iron core 1 is turned on, excitation windings 2a,
A magnetic path is formed by the current flowing through 2b, and an eddy current is induced in the metal service plate pl placed within the magnetic field, causing the metal service plate pl to heat up and rise in temperature. When the temperature of the metal service plate pl reaches a predetermined temperature, the power source E is turned off, and then the cylinder 3 is driven to move the rod 31 backward. As the rod 31 retreats, the movable arm 14a rotates about the pin 13 in a direction away from the fixed arm 14b due to the spring force of the tension spring, and the end face 15a also rotates away from the end face 15b.
The pressure on the upper surface of the metal service plate pl by the protrusion 17a of the end surface 16a is released. When the rod 31 is retracted to the maximum, the end face 1
The gap between 6a and 16b becomes wider. The metal service plate pl is taken out from between the widely spread end surfaces 16a and 16b, and the heating process is completed.

In order to confirm the effects of the present invention, the inventor conducted the following experiment.

Experimental Example 1 Specimen: Oval-shaped cast iron steak plate as shown in Figure 4 Dimensions: Overall length and width 280mm x 170mm Length and width of serving surface 240mm x 150mm Meat thickness 5mm Thickness including edge height 15mm Weight: Approximately 1.2Kg 2 Equipment used: The equipment shown in Figure 2 was used.
The cross section of the end face is almost the same as the mounting surface of the specimen.

Power supply used: 200V 50Hz 3 Experimental method: A thermocouple was fixed at the mark position on the serving surface of the steak plate shown in Figure 4, and all points were
The time required to raise the temperature to 200°C and other heating data were determined.

4 Experimental results...Each of the points marked with ○ on the periphery of the serving surface of the steak plate almost simultaneously, and the ○ in the center
The mark indicates a slight delay in heating and the temperature rose to 200°C in 60 seconds.
Power consumption during this period is 3.3KW, input KVA
was 3.74KVA, so the input power factor was 90%.
A faint low humming sound was heard while the power was on, but no noise was generated.

From the above experimental results, according to the present invention, it is possible to efficiently heat a steak plate in an extremely short time.
Moreover, it has become clear that the generation of noise can also be prevented.

In the above experimental example, an example was described in which a cylinder was used as a pressing mechanism to apply pressing force to metal service plates, but a strong compression spring or other pressing mechanism may be used instead.

According to the present invention, (1) the gap between the end faces is made variable by constructing the C-shaped iron core by pin-coupling two members; (2) Since the heating is performed with a very narrow gap between the end faces, the excitation current of the circuit is reduced and the power factor can be made extremely high. (2) Since the metal service plates are stably pressed and fixed between the end faces via the projections and heated, (1) the vibration of the plates is sufficiently suppressed and no noise is generated; (2) It is possible to maintain a good working environment in the cooking area, and (3) the pin joint rotating part that makes the gap between the end faces variable is located on the opposite side of the variable end face part, so (1) the rotating part can be Even if the sliding movement between the comb-like meshing parts is slight, it is possible to greatly widen or narrow the gap between the end faces. (2) Since the sliding movement is small, the sliding surface There is little wear, and (3) there is no need to provide a gap at the meshing end that would reduce the power factor.

(4) Since the end faces of the end faces are formed to approximately match the shape of the serving surface of metal service plates, (1) the gap between the end faces during heating can be covered regardless of the height of the edge of the plate; Since the gap can be made close to the wall thickness of the serving surface, which is the heating part, not only can the power factor be increased, but also (2) the serving surface can be heated and heated almost simultaneously; Heating is done by induction heating, so (1) heating takes a very short time, (2) energy efficiency is very high, (3) there is no environmental pollution, and (4) there is no need for ventilation or cooling equipment. There is no need for reinforcement, and (5) it is easier to control temperature, time, etc. compared to gas astragalus, so stable and accurate heating is possible, and (6) there is no risk of fire. The effect is extremely large.

[Brief explanation of drawings]

Fig. 1 is a front view for explaining an example of the induction heating method which is the premise of the present invention, Fig. 2a is a front view showing the state during heating in an embodiment of the present invention, Fig. 2b
is a right side view of the C-shaped core in FIG. 2a, FIG. 2c is a front view showing the non-heating state in the embodiment of the present invention, FIG. 3 is a circuit diagram of the present invention, and FIG. 4 is a diagram of the present invention. FIG. 3 is a plan view of a specimen used in an experimental example of the invention. 1... C-shaped core, 1a, 1b... U-shaped member,
11...Meshing part, 13...Pin, 14a, 14b
... Arm portion, 16a, 16b ... End surface, 2a, 2b
... Excitation winding, 17a, 17b ... Protrusion, 3, 3
1, 31...Press mechanism, E...Commercial frequency power supply, pl
...Metal service plate.

Claims (1)

[Claims] 1 Arrange the U-shaped members to face each other,
Their opposing ends on one side are formed into comb-shaped shapes that engage with each other, and they are connected with pins with the comb-shaped shapes interlocked. It has a shape that almost matches the shape of the serving surface, a protrusion is provided on each of the opposing end surfaces, and the pin connection point on one side is used as a fulcrum and is connected so that the gap between the opposing end surfaces on the other side is variable. A C-type iron core and an excitation winding wound on each of the arm portions of the iron core so as to form a magnetic path in the same direction within the core, and a pressing force applied in a direction to reduce the gap between the opposing end faces. A heating device for metal service plates, comprising a pressing mechanism for applying pressure.