KR200156200Y1 - The cubic cooking air circulation type of air-curtain refrigerator - Google Patents

Abstract

The present invention relates to a three-dimensional cold circulation air curtain refrigerator, in particular, the induction pipe (15) adjacent to the discharge port 12, so that the cold air circulation in the refrigerating chamber (R) can be circulated in three dimensions to improve the cooling function in the refrigerating chamber (R). Branch pipe 20 which is branched to communicate in direct downward from both sides of the) and is formed in communication with the end of the branch pipe 20 and the injection hole 22 through which a plurality of injection slits 24 are penetrated on the inner surface By providing a three-dimensional cold-circulating air curtain refrigerator, the cold air generated in the cross flow fan is appropriately distributed through the injection slits 24 of the discharge port 12 and the injection port 22 to be injected into the refrigerating chamber R, thereby providing the refrigerator. The cold air is effectively delivered to the storage of the, and the flow of cold air is circulated in three dimensions is designed to improve the cooling function of the refrigerating chamber (R).

Description

Stereo Cooling Air Curtain Refrigerator {THE CUBIC COOKING AIR CIRCULATION TYPE OF AIR-CURTAIN REFRIGERATOR}

The present invention relates to a three-dimensional cold-circulating air curtain refrigerator, and in particular, forming a branch pipe which is branched in direct communication downward on both sides of the induction pipe adjacent to the discharge port of the air curtain refrigerator, a plurality of injection slits at the lower end of the branch pipe By forming the injection port having a communication in communication, the cold air flow is distributed through the injection slit of the discharge port and the injection port to be injected into the refrigerating chamber, the cold air flow in the refrigerator is circulated in three dimensions by the different cold air flow of the discharge port and the injection port to cool the cooling room It relates to a three-dimensional cold air circulation air curtain refrigerator to improve the.

In general, a refrigerator is provided with a refrigerant heat circulation device to form a refrigeration cycle, and the temperature load of the air is converted in the evaporator of the refrigerant heat circulation device, that is, the cooler, and the cold air having the cooling load is discharged into the freezing and refrigerating compartments, respectively. In the method of circulating the cold air in the refrigerating chamber, the cold air generated in the cooler is flowed into the refrigerating chamber by the rotation of the circulation fan, and then the cold air is delivered to the stored food by ejecting the cold air to the cold air outlet provided on the rear wall and sidewall of the refrigerating chamber. In addition, the ejected cold air is introduced into the inlet installed in the upper front side of the refrigerating compartment and circulated to the cooler through a duct installed in the inside of the refrigerator.

However, in the conventional refrigerator, when the door is opened, the cold air of the refrigerating chamber is discharged from the air circulation path and discharged to the outside of the refrigerator, and free air flows into the refrigerator freely due to the buoyancy due to the density difference. By raising the temperature of the food, freezing and dew condensation caused by outside air occurred in each part of the refrigerating chamber, and the cooling function was increased due to the increase of the cooling time due to recooling and the temperature imbalance between the exposed portions of the cold air.

Therefore, recently, to supplement the above-mentioned disadvantages, a so-called Air-Curtain Refrigerator equipped with a cold air control device that blocks cold and outside air has been developed, and the air curtain refrigerator will be described with reference to the accompanying drawings. Is as follows.

In the accompanying drawings, Figure 1 is a schematic diagram showing the cold air circulation in the refrigerator compartment of the conventional air curtain refrigerator closed state, Figure 2 is a schematic diagram showing the cold air circulation in the opened refrigerator compartment of the conventional air curtain refrigerator, Figure 3 is This is a reference diagram showing the air circulation in the refrigerating chamber.

The conventional air curtain refrigerator includes a cooler 110 installed at the rear of the freezer compartment F, a cross flow fan 100 for forming cold air supplied from the cooler 110 into an airflow film, and a cross flow fan 100. An inlet 135 through which the generated airflow membrane is guided, a discharge port 125 through which the airflow membrane guided to the induction pipe 120 is ejected, and an inlet 135 for suctioning the airflow membrane in multiple stages from the rear wall of the refrigerating chamber R; A multi duct 130 for re-inducing the air sucked in the inlet 135 to the cross flow fan 100 is provided.

The cold air flow of the conventional air curtain refrigerator having such a configuration is, as shown in FIG. 1, in the state in which the door 140 of the refrigerating chamber R is closed, according to the set temperature of the controller (not shown). The temperature load is controlled. As the circulation fan 144 rotates at the same time as the heat exchange of the air is performed in the cooler 110 having the temperature load set therein, the cold air is led to the distribution duct 105 and the distribution port piped to both sides of the rear wall of the refrigerating chamber R ( (Not shown) is ejected to the refrigerating chamber (R).

And the cold air ejected into the refrigerating chamber (R) is to circulate the refrigerating chamber (R) to store the frozen storage, after which the cold air is lost to the inlet (135) is introduced into the refrigerating chamber (multi-duct 130) It flows into the collection pipe (not shown) piped in the center of the rear wall of R). The cold air flowing into the recovery pipe is supplemented with a temperature load through the cooler 110 to repeat the circulation process.

In addition, when the door 140 is opened, as shown in FIG. 2, first, when the door 140 of the refrigerating chamber R is opened, the door 140 is opened by the door switch 142 shown in FIG. 1. Is transmitted to a controller not shown, and the signal sensed by the controller stops the operation of the circulation fan 144 and simultaneously operates the cross flow fan 100.

And the cold air flow circulated in the refrigerating chamber (R) by the operation of the cross flow fan 100 is guided to the inlet 135, this cold air is not flowing to the recovery pipe through the multi-duct 130 in the inlet 135, the cross flow fan ( 100). This is because the operation of the circulation fan 144 is stopped and the cross flow fan 100 is operated so that the flow force of the cold air flows to the cross flow fan 100 without flowing to the recovery pipe because there is no flow force of the circulation fan 144.

Therefore, the cold air induced as described above is formed as a laminar flow airflow film in which air particles flow in an orderly manner by the crossflow fan 100. The laminar airflow membrane is led from the transverse flow fan 100 to the induction pipe 120, and the airflow membrane is formed by the induction pipe 120 at the lower end of the flow with some turbulence. In addition, the airflow membrane of the complex flow is formed at the end of the induction pipe 120 and is injected into the discharge port 125 located at the front upper end of the refrigerating chamber R. The airflow film is formed by the crossflow fan 100 and the discharge port 125. The flow velocity is formed by strong jets of 5 kPa or more.

As described above, the airflow film of the jet stream is injected into the refrigerating chamber (R) from the discharge port 125, which is formed in multiple stages on the rear wall of the refrigerating chamber (R) after circulating the refrigerating chamber (R) from the upper front side of the refrigerating chamber (R) to the rear. It is sucked into the inlet 135, in which the airflow membrane is designed to have a strong suction force from the upper side to the lower side so that the airflow membrane is effectively delivered to the lower end of the refrigerating chamber (R), the airflow membrane is L-shaped flow in the refrigerating chamber (R) Circulated to

In addition, the cold air circulated in this way is guided to the multi duct 130 at the inlet 135 and recycled to the crossflow fan 100 by the multi duct 130. That is, when the door 140 of the refrigerating chamber R is opened, the cool air is circulated only in the refrigerating chamber R without passing through the cooler 110 through the recovery pipe.

In addition, the air flow in the state in which the door 140 is opened as described above blocks air from the airflow membrane, thereby blocking cold air in the refrigerating chamber R, and when the door 140 of the refrigerating chamber R is closed again, the door switch. 142 transmits the closing signal of the door 140 to the controller, the controller stops the rotation of the cross flow fan (100). In the state where the rotation of the cross flow fan 100 is stopped and the airflow film is not formed, the circulation fan 144 is intermittently operated and the cooler 110 is operated in accordance with the set temperature to cool the air in the refrigerating chamber R. Supplied and circulated.

On the other hand, the air circulated in the refrigerating chamber (R) of the general refrigerator is composed of a synthetic airflow of air amount mixed in the outside and the refrigerating chamber (R), but as shown in Figure 3 in the refrigerating chamber (R) of the air curtain refrigerator The air circulated in the air is composed of a part of the air Q1 and the air flow Q2 mixed in the refrigerating chamber R, and a synthetic air stream of the primary air amount Q0 injected from the discharge port 125.

At this time, the airflow membrane, which is the primary air amount Q0 injected from the discharge port 125, blocks the outside air Q1 from flowing into the refrigerating chamber R as much as possible, thereby maintaining the balance of the flow field of the cold air circulated in the refrigerating chamber R. The temperature rise of the refrigerating chamber (R) is prevented.

However, the flow of cold air as described above is different from the case where the door 140 of the refrigerating chamber R is opened and closed, and thus the flow of air is not smooth. As the two-dimensional flow is injected from the top to the bottom and sucked into the inlet 135, the circulation path is simple, and thus the cold air flow in the refrigerating chamber R is not smooth. Accordingly, the cold air is transferred to the storage of the refrigerating chamber R. There was a problem that the cooling function of the refrigerator is lowered because it is not made effectively.

The present invention is devised to improve such a conventional problem, the technical problem of the present invention is to maintain the same cold air direction when the door of the refrigerating chamber is open and closed, the mutual air flow can be smooth, the upper part of the refrigerating chamber It is to improve the cooling function in the refrigerating chamber by smoothly flowing the cold air flow in the refrigerating compartment by circulating three-dimensional circulation path of the airflow membrane which is ejected from the lower side and performs the air curtain function.

The technical problem of the present invention as described above, in the air curtain refrigerator having an induction pipe for inducing cold air flow and the discharge port for ejecting the cold air flow flows into the refrigerating chamber, directly below both sides of the induction pipe adjacent to the discharge port It is achieved by providing a three-dimensional cold-circulating air curtain refrigerator comprising a branch pipe which is branched in communication with the room, and an injection hole formed in communication with an end of the branch pipe and having a plurality of injection slits penetrated on the inner side thereof.

1 is a schematic view showing a cold air circulation in a refrigerator compartment of a conventional air curtain refrigerator closed state,

Figure 2 is a schematic view showing a cold air circulation in the refrigerator compartment of the conventional air curtain refrigerator is opened,

3 is a reference diagram showing the air circulation in the refrigerating chamber in FIG.

Figure 4 is an installation state showing the configuration of the air curtain refrigerator according to the present invention,

5 is a schematic view showing the air circulation of the air curtain refrigerator according to the present invention.

<Explanation of symbols for main parts of drawing>

10: cross flow fan 12: discharge port

14: discharge partition 20: branch pipe

22: injection hole 24: injection slit

26a, 26b, 26c: guide plate 28: step

R: cold storage room

Figure 4 is an installation state showing the configuration of the air curtain refrigerator according to the present invention, Figure 5 is a schematic view showing the air circulation of the air curtain refrigerator according to the present invention, the three-dimensional cold air circulation air curtain refrigerator of the present invention When described with reference to the accompanying drawings as follows.

As shown in FIG. 4, the three-dimensional cold air circulation refrigerator of the present invention has a cross flow fan 10 installed at an upper rear side of the refrigerating chamber R, and an induction pipe for inducing cold air generated in the cross flow fan 10. 15 and the outlet port 12 for ejecting the cold air flowed into the induction pipe 15 into the refrigerating chamber R, and branched in direct communication from both sides of the induction pipe 15 adjacent to the outlet port 12. The branch pipe 20 is formed in communication with the end of the branch pipe 20 and includes a plurality of injection holes 22 penetrated through the plurality of injection slits 24 on the inner side.

That is, the induction pipe 15, the discharge port 12, and the branch pipe 20 to allow the cool air flowed into the induction pipe 15 to be ejected into the refrigerating chamber R through the discharge port 12 and the injection slit 24. ) And the injection slits 24 of the injection port 22 are formed in communication with each other.

A plurality of guide plates 26a, 26b, 26c are formed at the lower end of the injection slit 24, and the horizontal angles of the guide plates 26a, 26b, 26c are from the top. The angle is gradually increased toward the bottom, and the widths of the guide plates 26a, 26b, 26c are gradually longer from the top to the bottom.

In addition, a plurality of steps 28 are formed on the inner back surface of the injection hole 22, that is, the surface facing the injection slit 24.

On the other hand, the inlet (not shown) is formed below the rear wall of the refrigerating chamber (R) to suck the air flow membrane circulated in three dimensions and is connected to the multi duct (not shown), which is connected to the cross flow fan (10).

Referring to the operation of the present invention configured as described above are as follows.

First, when the door 19 of the refrigerating chamber (R) is closed, the cold air circulated in the same manner as the cold air flow of the conventional refrigerator is provided with a cooling load by a cooler (not shown). The air having the cooling load, that is, the cold air, becomes a cool air flow having a flow force formed by a circulation fan (not shown) in the cooler, is ejected to the refrigerator to circulate the refrigerating compartment R, and the circulated cold air is stored in the refrigerating compartment R. Deliver cold air to water. The cold air flow in which the cooling load is lost by transferring the cold air to the storage is sucked into the inlet formed at the bottom of the rear wall of the refrigerating chamber R, and the sucked cold air compensates for the loss of the cooling load according to the set temperature of the controller. Equipped cold air is circulated or stopped in the same path as the cold air in the refrigerating chamber is recycled.

Next, when the door 19 of the refrigerating chamber R is opened, the circulating cold air whose temperature load is exchanged in the cooler of the refrigerator flows into the cold air flow by the rotation of the cross flow fan 10, and the rotational force of the cross flow fan 10 The cold air stream is formed into the air stream. At this time, the fan shape of the cross flow fan 10 is formed to be horizontally long and the installation angle of the fan is installed to form a flow of air flow into a laminar flow (Laminar Flow), so the cold air flow formed in the cross flow fan 10 is It flows into the airflow film flow.

In addition, the induction pipe 15 induces a laminar airflow film generated in the cross flow fan 10, and a step (not shown) is formed at the lower end of the induction pipe 15, so that the lower flow of the laminar airflow film is partially turbulent. It is formed and flows in a complex flow.

On the other hand, the branch pipe 20 branched downward from both sides of the guide pipe 15 adjacent to the discharge port 12 and communicated with the guide pipe 15 flows through the guide pipe 15 to the discharge port 12. Part of the air stream membrane is blown off, and thus the cold air flow branched from the induction pipe 15 to the branch pipe 20 flows to the injection slit 24 of the injection hole 22 formed at the lower end of the branch pipe 20. Through each of them is ejected to the inside of the refrigerating chamber (R).

In addition, the plurality of guide plates 26a, 26b, and 26c formed at the lower end of the injection slit 24 in the injection hole 22 are formed such that their horizontal angles are gradually increased from the upper side to the lower side. When the cold air flow passing through 22 is ejected into the refrigerating chamber (R) through the injection slit 24, the cold air flow is gradually lowered.

In addition, as the lengths of the guide plates 26a, 26b, and 26c are also gradually increased from the upper part to the lower part, the cold air flow is prevented from being excessively discharged through the injection slit 24 located at the upper part. In addition, the step 28 formed on the inner rear surface of the injection port 22, which is the opposite surface of the injection slit 24, serves to convert the cold air in the injection port 22 into rapid turbulence before ejecting the cold air into the refrigerating chamber R.

Meanwhile, as described above, the airflow film is ejected into the refrigerating chamber R through the injection slit 24, but some airflow films are ejected into the refrigerating chamber R through the discharge port 12, and thus, a plurality of discharge partitions 14 formed in the discharge port 12. ) Prevents the air flow film from being excessively injected only into the discharge port 12.

Referring to the cold air flow of the present invention such a refrigerator in detail as follows.

First, when the door 19 of the refrigerating chamber R is opened, a door switch (not shown) generates an open signal of the door 19, and the open signal is input to a controller not shown. The open signal input in this way causes the controller to control the temperature load of the cooler according to the set temperature to start the cooler.

Therefore, the cooler having a temperature load generates cold air having a cooling load, and the cold air transfers the cooling load to the circulating air while mixing with the air flow, that is, the circulating air of the refrigerator, on the surface of the cooler.

In addition, when the circulating air, that is, the cold air, rotates the cross flow fan 10, cold air flow is generated to form cold air. The cold air flow is designed so that the fan shape of the cross flow fan 10 is formed as a laminar flow in which cold air flows in an orderly flow of air particles. This laminar flow of cold air flows from the transverse flow fan 10 to the induction pipe 15, and the cold air flow is formed by the stepped portion formed at the lower end of the induction pipe 15 to form some turbulence at the lower end of the flow.

As described above, the cold air flow formed by the complex flow in the induction pipe 15 is a flow of the previous stage for performing the air curtain function, and the flow rate of the cold air flow is limited in the relationship between the cold air generated in the cooler and the cold air flow in the cross flow fan 10. This limited cold air flow is guided toward the discharge port 12 provided in the upper end of the front surface of the refrigerating chamber (R) in the induction pipe (15) and injected into the refrigerating chamber (R).

At this time, the branch pipe 20 is formed so as to communicate directly downward from both sides of the inlet pipe 15 adjacent to the discharge port 12, the lower end of the branch pipe 20 is provided with a plurality of injection slits 24 22 is formed in communication, and the above-mentioned cold airflow is separated by the injection slit 24 to limit a part of the injection amount in the total flow rate of the cold airflow guided to the induction pipe 15.

The cold air flow separated and injected into the discharge port 12 is injected into the plane jets having a flow rate of 4 to 5 kPa, and the cold air flow of the jets is injected into the cold air flow film having a cold air load from the upper side to the lower side of the refrigerating chamber R. Perform the air curtain function. The cold air flow membrane that performs the air curtain function is designed so that the suction force of the inlet is stronger from the upper side to the lower side in order to effectively deliver to the bottom of the refrigerating chamber (R), the air flow membrane is circulated in the L-shaped flow in the refrigerating chamber (R). The cold air circulated from the upper front side to the lower rear side of the refrigerating compartment is introduced into the inlet formed in multiple stages on the rear wall of the refrigerating compartment (R), and then introduced into the multi duct.

On the other hand, the flow rate of the cold air flow that is formed as a complex flow in the induction pipe 15 to perform the air curtain function is generated in a limited relationship between the cold air generated in the cooler and the cold air flow in the cross flow fan 10. As described above, the total flow rate of the cold air flows from the induction pipe 15 to the discharge port 12 provided at the upper end of the front surface of the refrigerating chamber R, and at the same time, branches to the branch pipe 20 provided close to the discharge port 12.

The cold air flow branched into the branch pipe 20 flows into the injection port 22 from the branch pipe 20 as a composite flow of laminar flow and some turbulent flow. The cold air flow introduced into the injection port 22 from the branch pipe 20 is a plurality of guide plates 26a and 26b formed at the lower end of the injection slit 24 inside the injection port 22 before being led to the injection slit 24. The flow of cold air is separated while contacting the 26c).

In more detail, as the horizontal angles of the guide plates 26a, 26b, and 26c are formed to increase gradually from the top to the bottom, the cool air flow passing through the injection holes 22 causes the injection slits 24 to pass through. When it is ejected into the refrigerating chamber (R) through to act to gradually lower the blow angle of the cold air. That is, the cold air guided by the second guide plate 26b and jetted to the lower injection slit 24 than the jet angle of the cold air guided by the first guide plate 26a and jetted to the upper injection slit 24. The ejection angle of the gas is directed downward, and is similarly induced by the second induction plate 26b and induced by the third induction plate 26c than the ejection angle of the cold air ejected into the upper injection slit 24. The blowing angle of the cold air blown into the injection slits 24 is directed downward.

In addition, the guide plates 26a, 26b, and 26c are formed longer in width from the upper side to the lower side, and the cold air flowing into the injection port 22 is the first induction plate 26a to the third induction plate 26c. The amount of cold air is adjusted sequentially. That is, the amount of cold air guided by the first induction plate 26a and ejected to the upper injection slit 24 is higher than the amount of cold air guided by the second induction plate 26b and ejected to the lower injection slit 24. Similarly, the amount of cold air guided by the second guide plate 26b and jetted to the upper injection slit 24 is guided by the third guide plate 26c and jetted to the lower injection slit 24. It is smaller than the amount.

On the other hand, the cold air flow in the injection port 22 is guided by the guide plates 26a, 26b and 26c as described above, and the step 28 formed on the inner rear surface of the injection port 22, which is the opposite surface of the injection slit 24, is formed. Due to the flow of cold air rapidly formed turbulent flow. Therefore, the cold air jetted through the injection slit 24 is controlled by the amount of cold air and is formed into turbulent flow and jetted into the refrigerating chamber (R).

As described above, the cold air flow ejected from the injection slit 24 is mixed in the refrigerating chamber R together with air curtains injected from the discharge port 12 to block air exchange in the outside and the refrigerator to prevent cold air loss. The airflow is a two-dimensional flow flowing from the top to the bottom, and the cold air ejected from the injection slit 24 is injected as turbulent and the air curtain and its flow are combined, so that the flow circulates in the vortex as the flow progresses and flows in a constant direction. The cold air flow of the complex flow is mixed in the refrigerating chamber (R), respectively, and the laminar flow cold air of the discharge port 12 is in contact with the storage and is constantly flowed to the inlet, and the turbulence of the injection slit 24 is in contact with the storage. As a result of friction and viscous flow around the reservoir, the contact time with the reservoir increases, thereby improving the cooling rate.

This multi-dimensional flow of cold air maintains the circulation velocity while maintaining the circulation path of the laminar flow, and the turbulent flow flows in three dimensions in the refrigerating chamber (R) and at the same time effectively transmits the cold air of the storage.

In addition, the three-dimensional flow of cold air flows into the inlet in the refrigerating chamber (R) and the cold air flow circulating in the refrigerating chamber (R) is also sucked into the inlet. As the airflow membrane and the cold air flow into the inlet, the mixed cold air flows through the cooler according to the operation of the cooler. And some of the cold air flow through the cooler is recycled to the refrigerating chamber (R) by the circulation fan, the remaining cold air is formed back into the air flow film by the cross flow fan 10 to perform the air curtain function in front of the refrigerating chamber (R) Recirculation is to repeat the recirculation process to the crossflow fan 10 through the multi-duct.

As such, the present invention provides an air curtain having an induction pipe 15 for inducing cold air generated from the crossflow fan 10 and a discharge port 12 for ejecting the cold air flowed into the induction pipe 15 into the refrigerating chamber R. In the refrigerator, branch pipes 20 are formed on both sides of the induction pipe 15 adjacent to the discharge port 12 so as to communicate directly downward, and a plurality of injection slits 24 are provided at the lower end of the branch pipe 20. By forming the injection port 22 provided, when the refrigerator compartment R door 19 of the refrigerator is opened, the cool air generated in the cross flow fan 10 is ejected into the laminar flow from the discharge port 12, and the turbulent flow in the injection port 22. When it is converted into and injected through the injection slit 24 to circulate in the refrigerating chamber (R) in three dimensions, by the appropriate air flow of the turbulent flow and laminar flow described above effectively delivers cold air to the storage in the refrigerating chamber (R) and then multi-duct It is sucked and recycled to the crossflow fan 10.

As described above, according to the three-dimensional cold air circulation air curtain refrigerator according to the present invention, the cold air generated in the cross flow fan 10 is appropriately distributed to the discharge port 12 and the injection port 22, and then in the injection port 22. By dividing the cold air flow in multiple stages and injecting into the refrigerating chamber (R) through the injection slit 24, the different cold air flows ejected through the discharge port 12 and the injection port 22 is in contact with each other while the flow of the cold air in the refrigerator Since it is circulated in three dimensions, the cold air can be effectively delivered to the storage in the refrigerating chamber (R), which has a useful effect of improving the cooling function of the refrigerating chamber (R).

Claims (6)

In the air curtain refrigerator having an induction pipe (15) for inducing cold air flow and a discharge port (12) for ejecting the cold air flow flowing into the induction pipe (15) into the refrigerating chamber (R), Branch pipes 20 which are branched in direct communication from both sides of the induction pipe 15 adjacent to the discharge port 12; And An injection hole 22 formed in communication with an end of the branch pipe 20 and having a plurality of injection slits 24 penetrated at an inner side thereof; Three-dimensional cold air circulation air curtain refrigerator comprising a. [3] The three-dimensional cold circulation air curtain refrigerator according to claim 1, wherein a plurality of guide plates (26a) (26b) (26c) are formed at a lower end of the injection slit (24) inside the injection hole (22). 3. The three-dimensional cold circulation air curtain refrigerator according to claim 2, wherein the horizontal angles of the guide plates (26a) (26b) (26c) are gradually increased from the top to the bottom. 3. The three-dimensional cold-circulating air curtain refrigerator according to claim 2, wherein the width of the guide plates (26a) (26b) (26c) is formed to increase gradually from the top to the bottom. [3] The three-dimensional cold circulation air curtain refrigerator according to claim 1, wherein a plurality of steps (28) are formed on an inner side of the injection port (22) on opposite surfaces of the injection slit (24). The three-dimensional cold circulation air curtain refrigerator according to claim 1, wherein a plurality of discharge partitions (14) are formed in the discharge holes (12).