KR102661347B1 - roaster for gas and charcoal - Google Patents

Abstract

The present invention relates to a gas charcoal grill and a 'D roaster. To be described in more detail, a heat detection sensor installed to detect whether the gas supplied to the gas burner is leaking or abnormality detects the heat generated when the gas burner is ignited and the charcoal contained in the charcoal container. In order to prevent ignition and damage by heat generated during the ignition process, the heat detection part of the heat detection sensor is installed at a lower position than the burner head of the gas burner, and the burner support is installed so that only the heat detection part of the heat detection sensor is exposed. A heat shield cover is placed on the top to protect the heat sensor, and to prevent the heat shield cover from heating up and increasing the temperature, the outside air supplied by the blower is sprayed into the inside of the heat shield cover through the burner stand. It is characterized by cooling.

Description

Gas and charcoal roaster {roaster for gas and charcoal}

In the gas charcoal roaster of the present invention, a heat detection sensor installed to detect whether the gas supplied to the gas burner is leaking or abnormality is damaged by the heat generated when the gas burner is ignited and the charcoal contained in the charcoal container is ignited and generated during the ignition process. To prevent this, the heat detection part of the heat detection sensor is installed at a lower position than the burner head of the gas burner, and a heat blocking cover is placed on the upper part of the burner stand so that only the heat detection part of the heat detection sensor is exposed to detect heat. In order to protect the sensor and prevent the heat shield cover from heating and increasing the temperature, a gas charcoal roaster characterized by spraying external air supplied by a blower into the inside of the heat shield cover through a burner stand to cool it. It's about.

Generally, roasters are divided into those that can use charcoal exclusively and those that can also use gas as fuel.

In addition, since roasters are generally used indoors, those that circulate and filter combustion gas by forced circulation of a fan are known.

Recently, gas has been used to ignite the charcoal in the charcoal container, and once the charcoal is completely ignited, the supply of gas is cut off and the meat is grilled on the grill above the charcoal container by the combustion of the charcoal in the charcoal container, so the taste of the grilled meat is good. Many people are using gas and charcoal roasters.

A conventional gas charcoal roaster has an outer cylinder with an open top and an air supply hole and an air outlet hole for air supply and outflow, and a gas burner is installed in the center of the bottom of the outer cylinder.

The lower part of the gas burner is connected to a gas supply pipe that supplies gas to the interior, and flame holes through which flame is drawn out when the gas is ignited are formed at regular intervals around the upper circumference.

In addition, inside the outer cylinder, there is an inner cylinder installed on the upper part of the gas burner, a charcoal cylinder installed on the upper part of the burner head of the gas burner and containing charcoal inside the inner cylinder, and an ash catch plate is installed on the bottom of the charcoal cylinder.

In addition, an oil tank and a grill are installed inside the outer cylinder so that they are located at the top of the charcoal tank.

An air purifying means is installed at the lower part of the outer cylinder, and the configuration includes a motor that forcibly sucks in and discharges the contaminated air in the outer cylinder through the air purifying means, and a control means that controls the operation of the motor and the gas burner.

Meanwhile, a spark plug is installed around the gas burner to ignite the supplied gas, and a heat detection sensor is installed to check whether the gas supplied inside the gas burner is ignited and operates normally.

As shown in Figure 8, the body of the heat sensor has a heat detection part that detects heat at the top, and metal wires and wires on the inside and sides that connect the detected signal to the control means are attached to the heat sensor by soldering. .

In addition, the installation location of the heat sensor is mainly adjacent to the bottom of the charcoal container, and the heat sensor is installed at the top of the flame hole to be close to the flame hole of the gas burner.

However, as described above, if the heat sensing part of the heat detection sensor is close to the bottom of the charcoal container and is installed at the same or higher position as the flame hole, the thermal power ignited in the flame hole of the gas burner and the temperature of more than 1000°C discharged from the charcoal container will cause damage to the heat sensing part. The metal wires and the solder attaching them melt and separate due to the high temperature, and the metal wires and electric wires also melt and become damaged, making it impossible to check whether gas is leaking or being supplied by heat detection.

The operating principle of the heat sensor is that gas is supplied into the gas burner by operating the gas supply lever in the control means, and at the same time, the gas is ignited by the spark plug and a flame is sprayed through the flame hole, and the heat sensor ignites the gas. If the heat generated by the ignition of the charcoal in the charcoal container is above a certain temperature, this can be detected to confirm that the supplied gas is operating normally. If gas is supplied to the gas burner and the temperature of the detected heat is low, the gas Recognizing that it will not ignite, cut off the gas supply so that you can safely use the gas charcoal roaster.

However, conventional gas charcoal roasters are installed close to the charcoal tank and the flame hole of the gas burner, and the heat generated during ignition frequently melts the parts and solder parts of the heat sensor, causing malfunctions, thereby raising the risk of safety accidents due to gas leaks. In order to prevent this, there is the inconvenience of having to periodically inspect the thermal sensor and replace it when damaged.

Korean Utility Model Application No. 20 - 2002 - 0022903 "Gas charcoal ignition type roaster"

In order to solve the above problems, the gas charcoal roaster of the present invention installs a heat sensor that detects heat low to be as far away from the charcoal container and the flame hole as possible to check whether the gas supplied to the gas burner is ignited. The purpose is to protect the metal wire and the soldered parts of the electric wire from melting, and to protect the heat detection sensor from melting from the heat generated from the gas burner and charcoal canister.

As a means of solving the above problem, the gas charcoal roaster of the present invention includes an external cylinder, a blower at the bottom of the external cylinder that supplies external air to a burner stand installed inside the external cylinder, and a gas burner, a heat sensor, and an upper part of the spark plug drawn out from the inside of the external cylinder. It consists of a burner stand installed as much as possible, the gas burner and the upper part of the ignition plug are drawn out from the upper surface of the burner stand, and the heat detection sensor is composed of a heat blocking cover that is seated and sealed at the bottom so that the heat detection part is drawn out, to prevent the heat generated from the ignited gas and charcoal. To prevent the heat sensor from being damaged by heat, we provide a gas charcoal roaster that blocks heat and prevents the temperature from rising by cooling by external air supplied to the inside of the heat shield cover by a blower.

As described above, in the gas charcoal roaster of the present invention, the heat detection part of the heat detection sensor is located lower than the flame hole of the gas burner, and then a heat blocking cover is placed so that only the heat detection part is exposed, so that the heat generated from the ignited gas and charcoal is directly By blocking the transfer to the entire heat sensor, it prevents the metal wires and soldered parts of the heat sensor from melting, improving durability, and also blows outside air through a blower to prevent the temperature of the heat blocking cover from rising. By spraying and cooling the inside of the heat shield cover, the cooling effect is maximized and the durability of the heat sensor is improved.

In addition, in the present invention, sensor fixing protrusions are arranged in a concavo-convex shape along the inner peripheral surface of the sensor insertion hole formed in the burner pedestal, and a sensor cooling hole is formed between the sensor fixing protrusions, so that only the sensor fixing protrusions contact and are fixed to the outer peripheral surface of the heat detection sensor. , external air is sprayed through the sensor cooling hole to cool the heat detection sensor and sensor fixing protrusions, thereby preventing the temperature from rising.

In addition, the present invention has the effect of improving the heat detection function by forming a plurality of heat detection holes in the vertical direction on the side of the gas burner, so that heat can be detected regardless of the height of the heat detection sensor.

Figure 1 is an exploded perspective view showing the gas charcoal roaster of the present invention.
Figure 2 is a combined perspective view showing the gas charcoal roaster of the present invention.
Figure 3 is a combined cross-sectional view showing the gas charcoal roaster of the present invention.
Figure 4 is an enlarged cross-sectional view of the burner stand and heat shield cover in the gas charcoal roaster of the present invention.
Figure 5 is a plan view showing the burner stand in the gas charcoal roaster of the present invention.
Figure 6 is a perspective view showing the heat shield cover removed from the gas charcoal roaster of the present invention.
Figure 7 is a perspective view showing the heat shield cover combined in the gas charcoal roaster of the present invention.
Figure 8 is an enlarged perspective view showing a heat detection sensor.
Figure 9 is a perspective view showing the combination of a heat sensor and a fixing bracket in the gas charcoal roaster of the present invention.
Figure 10 is a perspective view showing a heat shield cover in the gas charcoal roaster of the present invention.
Figure 11 is a cross-sectional view showing the heat shield cover in the gas charcoal roaster of the present invention.
Figure 12 is a plan view showing that external air is supplied by a blower installed in the blower in the gas charcoal roaster of the present invention.

In order to achieve the above purposes and effects, the present invention will be described in detail with the accompanying drawings as follows.

Figure 1 is an separated perspective view showing a gas charcoal roaster of the present invention, Figure 2 is a combined perspective view showing a gas charcoal roaster of the present invention, and Figure 3 is a combined cross-sectional view showing a gas charcoal roaster of the present invention. , Figure 4 is an enlarged cross-sectional view of the burner stand and heat shield cover in the gas charcoal roaster of the present invention, Figure 6 is a perspective view showing the heat shield cover removed in the gas charcoal roaster of the present invention, and Figure 7 is a gas charcoal roaster of the present invention. This is a perspective view showing the heat shield cover combined in a charcoal roaster, and Figure 8 is an enlarged perspective view showing the heat detection sensor.

The gas charcoal roaster (1) of the present invention has a heat-blocking cover that blocks heat to prevent the heat detection sensor (7) installed to detect abnormal gas leaks from melting by the heat generated from the ignited gas and charcoal. It is installed, and in order to prevent the internal temperature of the heat shield cover from rising, some of the external air supplied to the charcoal by a blower is cooled by supplying it to the inside of the heat shield cover and discharging it.

The gas charcoal roaster (1) is largely composed of a blower (29), an outer cylinder (2), an inner cylinder (3), a charcoal cylinder (15), a heat sensor (7), a gas burner (4), and a spark plug (8). It is composed.

The outer cylinder 2 of the gas charcoal roaster is open at the top, and a portion of the bottom is perforated with the blower 29 located at the bottom.

The blower 29 located at the lower part of the outer cylinder 2 has a blower 27 installed inside and supplies external air to the inside of the burner support 19 installed inside the outer cylinder 2, and some of it is inside the heat shield cover. Some of it is supplied to the charcoal container to ignite and burn well, and it also has the function of controlling the heat of the charcoal according to the wind power of the supplied air.

The gas burner 4 located on the bottom of the outer cylinder 2 is installed upward, and when the gas supplied through the flame hole 12 arranged along the circumference of the burner head 5 located at the top is ejected, it is ignited by the ignition plug. It ignites and ignites the charcoal contained in the charcoal container.

The gas supply pipe 11 inserted into the outer cylinder 2 is connected to the gas burner 4 and supplies gas.

The gas burner 4 is located below the flame hole 12 and has a plurality of heat-sensing holes 9 arranged in a vertical direction so that heat can be detected by the heat-sensing sensor 7.

The burner support 19 inserted into the outer cylinder 2 is in the shape of a box, the bottom of which is open and is perforated with the blower 29, the upper surface is sealed, and the burner head 5 of the gas burner 4 is located in the center. A gas burner outlet hole 21 is formed to be inserted and protruded upward, and the heat detection part 18 of the heat detection sensor 7 is inserted and withdrawn from a portion of the upper surface located on one side of the gas burner outlet hole 21. An insertion hole 20 and a spark plug outlet hole 30 into which the spark plug 8 is inserted and withdrawn are formed, and a heat shield cover 13 mounted on the top is formed around the gas burner outlet hole 21 with a blower. The heat shield cover cooling holes 34 are arranged at regular intervals to cool by spraying external air supplied by (28), and the charcoal container 15 located at the top and arranged at regular intervals around the side of the enclosure is equipped with a blower ( The charcoal container air supply hole 24 that supplies external air is formed integrally with 27) and is seated on the bottom surface of the outer container 2.

The fixing bracket 10 installed inside the burner stand 19 has a vertical piece installed in a vertical direction from the bottom surface of the outer cylinder 2, and a horizontal piece extending at a right angle at the top of the vertical piece has a sensor insertion hole 20'. ) is formed and the heat detection sensor (7) is inserted.

The lower part of the heat detection sensor 7 is inserted into the burner stand 19 through the sensor insertion hole 20', and the heat detection part 18 located at the top protrudes in the direction of the burner head 5 and forms a flame hole 12. ) is installed in a lower position and detects heat.

The heat detection sensor 7 is formed in a structure in which a heat detection part is located on the upper part of the body, and a metal wire or electric wire is attached to the outer circumference or the inside by a soldering method.

The thermal sensor 7 typically has durability that can withstand temperatures up to 800°C.

The lower part of the spark plug (8) is inserted into the burner stand (19) through the gas burner outlet hole (21), and the upper part is installed to protrude in the direction of the burner head (5) to supply gas to the gas burner (4). ignites.

The heat blocking cover 13 is sealed on the top and sides to protect the heat sensor 7 by blocking the heat generated from the ignited charcoal and gas by seating the bottom on the top of the burner stand 19, and the bottom is sealed. In the open state, a gas burner outlet hole 21' is formed on the upper surface, into which the burner head 5 of the gas burner 4 is inserted and pulled out, and a sensor is drawn out on the upper surface located on one side of the gas burner outlet hole 21'. A hole 14 and a spark plug outlet hole 30' are formed, so that only the heat sensing part of the heat detection sensor is output from the sensor outlet hole and the spark plug 8 is output from the spark plug outlet hole 30'.

An inner cylinder (3) is inserted into the outer cylinder (2), and the inner cylinder (3) is located at the top of the gas burner (4).

A charcoal tank supporter (6) is located inside the inner cylinder (3), and the charcoal tank supporter (6) has a tubular shape with perforated upper and lower parts, the lower part of which is seated on the upper part of the burner support (19), and the upper part supports the lower part of the charcoal container (15). In addition, the bottom surface of the charcoal container and the heat sensor are spaced as much as possible to prevent the heat sensor from being damaged by the heat generated from the charcoal container.

The charcoal container supporter (6) concentrates and supplies the thermal power generated when the gas of the gas burner is ignited to the charcoal container, and external air supplied from the blower is also supplied to the charcoal container without being dispersed inside the outer container, thereby increasing the thermal power of the charcoal, thereby increasing the grilling plate. You can use it to grill as well as to cook hotpots and stews using a hotpot pot.

Additionally, you can remove the charcoal container and cook hotpots and stews using a hotpot pot on the top of the charcoal container supporter.

Instead of using the charcoal container supporter (6), the charcoal container can be used by seating it directly on the upper part of the burner support (19).

The charcoal container (15) inserted inside the inner container (3) is perforated at the top and bottom, and a charcoal support plate (16) is installed on the bottom to contain charcoal, and a blower (27) is placed around the edge of the bottom to cover the charcoal contained inside. ) Charcoal air inlet holes 25 are arranged at regular intervals to supply air supplied by ).

The gas control unit 32 located on one side of the outer cylinder 2 controls the blower 28, the heat sensor 7, and gas supply.

The gas charcoal roaster (1) has a gas burner (4) located on the bottom of the outer cylinder (2), a heat sensor and a spark plug are located close to the outer circumferential surface of the gas burner (4), and the burner support is positioned from the upper direction. It is inserted so that only the upper part of the gas burner, heat sensor, and spark plug protrudes.

When the heat shield cover is placed on the upper surface of the burner pedestal, only the upper part including the burner head protrudes, the heat detection sensor protrudes only the heat detection part located at the top, and the spark plug protrudes close to the flame hole of the gas burner.

The sensor outlet hole 14 of the heat-blocking cover 13 is formed in a dome shape to protrude upward, so that only the heat-sensing part of the heat-sensing sensor protrudes and the remaining part is sealed so as not to be exposed, thereby blocking heat.

A charcoal tank supporter is seated on the upper surface of the burner support so that a gas burner, a heat sensor, and a spark plug are located inside, a charcoal container is located on the top of the charcoal container supporter, a charcoal support plate is mounted on the bottom of the charcoal container, and a charcoal support plate is placed on the top of the charcoal support plate. After the charcoal is heated, place a grilling plate on top of the inner container and use it.

The control unit supplies gas into the gas burner, and the gas flame generated by igniting the gas by operating the spark plug travels to the bottom of the charcoal container, heats the charcoal, and ignites it.

In addition, when the control unit operates the blower, the blower supplies external air into the burner stand, and some of it passes through the charcoal box supporter through the charcoal box air supply hole formed on the side of the burner stand, and is then supplied into the inside of the charcoal box through the charcoal air inlet hole formed at the bottom of the charcoal box. It induces ignition and controls the firepower of the charcoal by the strength of air pressure.

In addition, some of the air supplied inside the burner pedestal is continuously supplied through the cooling hole of the heat shield cover located on the upper surface of the burner pedestal, causing the temperature of the space between the heat shield cover and the burner pedestal to rise due to the heat generated from the gas and charcoal. Cool to prevent it from happening.

The air supplied inside the heat shield cover is discharged into the charcoal container through the sensor outlet hole and spark plug outlet hole formed in the heat shield cover.

One or more air discharge holes 22 are formed in the outer cylinder 2 to prevent the internal temperature of the outer cylinder from rising due to external air flowing into the outer cylinder, and the heat detection sensor detects the heat generated from the ignited gas and charcoal of the gas burner. It blocks the temperature from rising above a certain level due to heat and prevents the soldered area from melting due to heat, improving durability.

As described above, the thermal sensor is sealed with a heat blocking cover so that only the heat sensing part is exposed, direct heat transfer is blocked, and the heat blocking cover is cooled by continuously supplied external air so that the heat sensor can withstand the heat. It is a configuration that improves durability by maintaining the temperature below the appropriate temperature.

Figure 10 is a perspective view showing the heat shield cover in the gas charcoal roaster of the present invention, and Figure 11 is a cross-sectional view showing the heat shield cover in the gas charcoal roaster of the present invention.

The heat shield cover can be maintained at a distance from the burner stand by bending and extending downward around the edge of the plate-shaped upper surface, and the sensor outlet hole 14 formed on the upper surface has a dome shape that protrudes upward. It is formed so that only the heat detection part 18 of the heat detection sensor 7 protrudes.

Figure 9 is a perspective view showing the heat detection sensor and the fixing bracket combined in the gas charcoal roaster of the present invention. The diameter of the sensor insertion hole formed in the fixing bracket is larger than the diameter of the heat detection sensor, resulting in a gap being formed in the sensor insertion hole. If the inner peripheral surface does not directly contact the outer peripheral surface of the thermal sensor and has the effect of cooling the thermal sensor by passing air, it supports the thermal sensor so that it does not move beyond a certain angle.

The heat detection sensor 7 is fixed so as not to move in the sensor insertion hole 20 formed in the burner stand 19.

Figure 10 is a perspective view showing the heat shield cover in the gas charcoal roaster of the present invention, and Figure 11 is a cross-sectional view showing the heat shield cover in the gas charcoal roaster of the present invention.

The sensor insertion hole 20 of the burner stand 19 is formed with a sensor fixing protrusion 26 in a convex-convex shape along the inner peripheral surface to fix the heat detection sensor 7, and a sensor cooling unit is provided between the sensor fixing protrusions 26. It is a structure in which a hole 33 is formed to cool the outer peripheral surface of the thermal sensor 7 by external air supplied by the blower 27.

Therefore, the sensor insertion hole 20 of the burner stand 19 minimizes the area in contact with the heat detection sensor 7, and the outer peripheral surface of the heat detection sensor 7 is continuously covered by a blower through the sensor cooling hole 33. When cooled by the supplied external air, it is supplied to the inside of the heat shield cover, preventing the air inside the heat shield cover from rising, protecting the heat sensor and improving durability.

Figure 12 shows the flow of air supplied to the inside of the outer cylinder by passing external air through a portion of the outer cylinder by a blower installed in the blower in the gas charcoal roaster of the present invention.

1: Gas charcoal roaster 2: External cylinder
3: Inner cylinder 4: Gas burner
5: Burner head 6: Charcoal can supporter
7: Heat sensor 8: Spark plug
9: Heat detection hole 10: Fixing bracket
11: gas supply pipe 12: flame hole
13: Heat blocking cover 14: Sensor outlet hole
15: Charcoal container 16: Charcoal support plate
18: heat detection unit 19: burner stand
20, 20': sensor insertion hole 21, 21': gas burner outlet hole
22: air outlet hole
24: Charcoal air supply hole 25: Charcoal air inlet hole
26: Sensor fixing protrusion 27: Blower
29: blowing unit 30, 30': spark plug outlet hole
32: control unit 33: sensor cooling hole
34: Heat shield cover cooling hole

Claims (5)

In a gas charcoal roaster,
An external cylinder (2) whose upper part is open and whose bottom part is perforated with the upper part of the blowing unit (29) located at the lower part,
A blowing unit (29) located at the lower part of the outer cylinder (2), with a blower (27) installed inside, to supply external air into the burner support (19) installed inside the outer cylinder (2),
A gas burner (4) installed upward from the bottom of the outer cylinder (2) to eject gas supplied through flame holes (12) arranged along the circumference of the burner head (5) located at the upper portion;
The gas burner (4) includes a plurality of heat-sensing holes (9) located below the flame hole (12) arranged vertically so that heat can be detected by a heat-sensing sensor (7),
A gas supply pipe (11) inserted into the outer cylinder (2) and connected to the gas burner (4) to supply gas,
Inside the outer cylinder (2), the bottom surface is open and perforated with the blowing unit (29) in the shape of a box, the upper surface is sealed, and the burner head (5) of the gas burner (4) is inserted and protrudes upward in the center to provide gas. A burner outlet hole 21 is formed, and a sensor insertion hole 20 into which the heat detection part 18 of the heat detection sensor 7 is inserted and withdrawn is located on a portion of the upper surface located on one side of the gas burner outlet hole 21, and an ignition A spark plug outlet hole 30 into which the plug 8 is inserted and withdrawn is formed, and a heat shield cover 13 mounted on the top is formed around the gas burner outlet hole 21 and supplied by the blower 28. External air is supplied by a blower (27) to the thermal barrier cover cooling holes (34) arranged at regular intervals to cool by spraying air, and to the charcoal container (15) arranged at regular intervals around the side of the enclosure and located at the top. A burner support (19) in which the charcoal tank air supply hole (24) is integrally formed and is seated on the bottom of the outer cylinder (2),
Inside the burner support 19, a vertical piece is installed in the vertical direction from the bottom surface of the outer cylinder 2, and a sensor insertion hole 20' is formed in a horizontal piece extending at a right angle at the top of the vertical piece, so that a heat detection sensor ( 7) a fixing bracket (10) for inserting; class,
The lower part is inserted into the burner stand 19 through the sensor insertion hole 20', and the heat sensing part 18 located at the top protrudes in the direction of the burner head 5 and is installed at a lower position than the flame hole 12. A heat detection sensor (7) that detects heat,
A spark plug ( 8) Wow,
The bottom is seated on the top of the burner stand 19, and the top and sides are sealed to protect the heat sensor 7 by blocking the heat generated from the ignited charcoal and gas. The bottom is open, and the top is sealed with gas. A burner outlet hole 21' is formed to insert and withdraw the burner head 5 of the gas burner 4, and a sensor outlet hole 14 and a spark plug are provided on the upper surface located on one side of the gas burner outlet hole 21'. A heat shield cover (13) in which outlet holes (30') are each formed so that only the heat sensing part of the heat detection sensor is drawn out from the sensor outlet hole and a spark plug (8) is drawn out from the spark plug outlet hole (30');
Inside the outer cylinder (2), an inner cylinder (3) inserted to be located at the top of the gas burner (4),
Inside the inner cylinder (3), there is a charcoal tank supporter (6) in the shape of a tube with upper and lower portions perforated, the lower part of which is seated on the upper part of the burner stand (19), and the upper part of which supports the lower part of the charcoal container (15);
Inside the inner cylinder (3), a charcoal support plate (16) is installed on the bottom surface in a perforated state with the upper and lower parts to contain charcoal, and air supplied by the blower (27) to the charcoal contained inside is placed around the edge of the bottom surface. A charcoal container (15) arranged with charcoal air inlet holes (25) perforated at regular intervals to supply water,
A gas charcoal roaster, characterized in that a blower (28), a heat sensor (7), and a gas control unit (32) for controlling gas supply are installed on one side of the outer cylinder (2). delete The method of claim 1, wherein the sensor insertion hole 20 of the burner stand 19 is formed with a sensor fixing protrusion 26 in a concavo-convex shape along the inner peripheral surface to fix the heat detection sensor 7, and the sensor fixing protrusion ( 26) A gas charcoal roaster, characterized in that a sensor cooling hole 33 is formed between the sensors, and the outer peripheral surface of the heat detection sensor 7 is cooled by external air supplied by the blower 27.
The gas charcoal roaster according to claim 1, wherein the sensor outlet hole (14) of the heat blocking cover (13) is formed in a dome shape to protrude upward. The gas charcoal roaster according to claim 1, wherein one or more air discharge holes (22) are formed in the outer cylinder (2).