Ice maker

Abstract

In an ice maker in which a circumferentially extending refrigerant passage is formed between an inner cylinder and an outer cylinder that are concentrically erected so that their axes are vertical, the objective is to reduce costs while increasing the precision of the tight seal between the outer cylinder and the partition member. [Solution] The ice maker 10 comprises an inner cylinder 21 erected with its axial direction being vertical, an outer cylinder 22 concentrically disposed outside the inner cylinder 21 and forming a refrigerant space RS through which refrigerant can pass between it and the inner cylinder 21, and a partition member 23 interposed between the inner cylinder 21 and the outer cylinder 22 to form a refrigerant passage extending circumferentially within the refrigerant space RS. The inner surface of the inner cylinder 21 is cooled by vaporizing the refrigerant passing through the refrigerant passage RP, and water is frozen on the inner surface of the inner cylinder 21 to make ice. The outer cylinder 22 is formed into a cylindrical shape by providing a welded joint 22a where the ends on both sides in the circumferential direction of a sheet metal member curved along the outer surface of the partition member 23 are joined by welding.

Description

Technical Field

[0001] The present invention relates to an ice maker that cools the inner peripheral surface of an inner cylinder by passing a refrigerant through a refrigerant passage formed between an inner cylinder and an outer cylinder that are concentrically erected with the axial direction being vertical, and freezes ice-making water on the inner peripheral surface of the inner cylinder to make ice.

Background Art

[0002] Patent Document 1 discloses an invention of an ice-making device. This ice-making device concentrically installs an inner cylinder inside an outer cylinder to form an evaporation space between the two cylinders, supplies a refrigerant into the evaporation space to cool the inner wall of the inner cylinder, and supplies ice-making water to the inner wall of the inner cylinder to form an ice layer, which is peeled off by a rotary blade to produce flaky ice. A spiral high-spiral fin is provided on the outer peripheral surface of the inner cylinder, and the evaporation space is formed with a spiral refrigerant passage that is continuous up and down. Further, as another configuration of Patent Document 1, an annular high-fin member is arranged on the outer peripheral surface of the inner cylinder at a predetermined interval up and down, and a notch for passing the refrigerant upward is formed in the high-fin member. The notches of the high-fin members arranged up and down are arranged at positions symmetric to each other with respect to the center of the inner cylinder so as to be shifted from each other in the horizontal direction. The evaporation space between the inner cylinder and the outer cylinder is formed with a zigzag refrigerant passage that is continuous up and down by the high-fin members arranged so that the notches are shifted from each other in the horizontal direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the ice-making apparatus (ice maker) described in Patent Document 1, a partition member such as a highly spiral fin or a highly finned member is provided between the inner cylinder and the outer cylinder, and a refrigerant passage extending in the circumferential direction is formed in the evaporation space between the inner cylinder and the outer cylinder by the partition member such as the highly spiral fin or highly finned member. Patent Document 1 does not describe a joining means for joining the partition member such as the highly spiral fin or highly finned member to the inner cylinder, or a joining means for joining the partition member such as the highly spiral fin or highly finned member to the outer cylinder. For example, if a highly spiral fin or highly finned member is joined to the inner cylinder by brazing or welding, and then a pre-formed cylindrical outer cylinder is joined to the outer circumference of the highly spiral fin or highly finned member joined to the inner cylinder, if a gap is formed between the outer cylinder and the outer circumference of the highly spiral fin or highly finned member, the refrigerant will move through this gap and will not move along the outer surface of the inner cylinder in the refrigerant passage, resulting in a decrease in the cooling efficiency inside the inner cylinder. Furthermore, while it is possible to join the outer cylinder to the outer circumference of a highly spiral fin or highly finned member without gaps by increasing the precision of the inner diameter of the outer cylinder which is formed in advance, increasing the precision of the inner diameter of the outer cylinder increases costs. The present invention aims to improve the precision of the contact between the outer cylinder and the partition member while reducing costs in an ice maker in which a refrigerant passage extending in the circumferential direction is formed between an inner cylinder and an outer cylinder that are concentrically erected so that their axial direction is vertical, by a partition member. [Means for solving the problem]

[0005] To solve the above problems, the present invention provides an ice maker comprising: an inner cylinder erected with its axial direction being vertical; an outer cylinder concentrically disposed outside the inner cylinder to form a refrigerant space through which a refrigerant can pass; and a partition member interposed between the inner cylinder and the outer cylinder to form a refrigerant passage extending circumferentially within the refrigerant space. The ice maker cools the inner surface of the inner cylinder by vaporizing the refrigerant passing through the refrigerant passage, and freezes ice-making water on the inner surface of the inner cylinder to make ice. The present invention provides an ice maker characterized in that the outer cylinder is formed in a cylindrical shape by providing a welded joint where the ends on both sides in the circumferential direction of a sheet metal member curved along the outer surface of the partition member are joined by welding.

[0006] In the ice maker configured as described above, the outer cylinder is formed into a cylindrical shape by providing welded joints where the ends on both sides in the circumferential direction of a sheet metal member curved along the outer surface of the partition member are joined by welding. Since the outer cylinder is a sheet metal member curved along the outer surface of the partition member, it can be made to fit tightly against the outer surface of the partition member with high precision while keeping costs down compared to a pre-formed cylindrical shape. Furthermore, since the outer cylinder has welded joints where the ends on both sides in the circumferential direction of the sheet metal member are joined by welding, the outer cylinder shrinks after the ends on both sides in the circumferential direction of the sheet metal member are joined by welding, causing the outer cylinder to shrink radially and fit tightly against the outer surface of the partition member, making it difficult for gaps to form.

[0007] In the ice maker configured as described above, it is preferable that the circumferential length of the sheet metal member is shorter than the circumferential length of the outer surface of the partition member, creating a gap between the ends on both sides in the circumferential direction, and that the welded joint is formed by joining the sheet metal member with the ends on both sides in the circumferential direction filled with welding material. When the ends on both sides in the circumferential direction of the sheet metal member are joined with welding material, the ends on both sides in the circumferential direction of the sheet metal member are heated together with the welding material and expand, and as the ends on both sides in the circumferential direction of the sheet metal member and the welding material cool, they contract, causing the outer cylinder to contract radially and come into close contact with the outer surface of the partition member, making it less likely for gaps to form and improving the accuracy of the contact between the outer cylinder and the partition member.

[0008] In the ice maker configured as described above, it is preferable that the outer cylinder is equipped with a heating and straightening section that expands and then contracts after being heated in at least a portion of it. By providing the outer cylinder with a heating and straightening section that expands and then contracts after being heated in at least a portion of it, the outer cylinder is compressed in at least a portion by the heating and straightening section, thereby increasing the accuracy of the contact with the partition member. In this case, it is preferable that the heating and straightening section is provided so as to extend vertically from the outer cylinder together with the welded joint, and is located on the side of the outer cylinder opposite to the welded joint in the radial direction. The outer cylinder is compressed from both radial sides by the welded joint and the heating and straightening section, thereby increasing the accuracy of the contact between the outer cylinder and the partition member. Furthermore, it is preferable that the heating and straightening section extends vertically from the outer cylinder together with the welded joint, and is located at multiple locations in the circumferential direction of the outer cylinder, with these multiple heating and straightening sections, including the welded joint, being arranged at equal intervals in the circumferential direction of the outer cylinder. The outer cylinder is compressed throughout the entire circumferential direction by the heating and straightening sections arranged at equal intervals in the circumferential direction and the multiple welded joints, thereby increasing the accuracy of the contact between the outer cylinder and the partition member. Furthermore, it is preferable that the heat-straightening section is arranged to extend circumferentially along the partition member of the outer cylinder. The outer cylinder shrinks circumferentially along the partition member by the heat-straightening section, thereby improving the degree of contact between the outer cylinder and the partition member.

[0009] In the ice maker configured as described above, a refrigerant introduction pipe for introducing refrigerant into the refrigerant passage is welded to the lower part of the outer cylinder, and it is preferable that at least a portion of the welding point of the refrigerant introduction pipe to the lower part of the outer cylinder be at the height where the partition member is positioned. Because at least a portion of the welding point of the refrigerant introduction pipe to the lower part of the outer cylinder is at the height where the partition member is positioned, the outer cylinder contracts as the welding point cools, causing the outer cylinder to adhere closely to the outer surface of the partition member, making it less likely for gaps to form, and thus improving the accuracy of the adhesion between the outer cylinder and the partition member.

[0010] In the ice maker configured as described above, a refrigerant outlet pipe for guiding refrigerant from the refrigerant passage is welded to the upper part of the outer cylinder, and it is preferable that at least a portion of the welding point of the refrigerant outlet pipe to the upper part of the outer cylinder be at the height where the partition member is positioned. Because at least a portion of the welding point of the refrigerant outlet pipe to the upper part of the outer cylinder is at the height where the partition member is positioned, the outer cylinder contracts as the welded area cools, causing the outer cylinder to adhere tightly to the outer surface of the partition member, making it less likely for gaps to form, and thus improving the accuracy of the adhesion between the outer cylinder and the partition member.

[0011] In the ice maker configured as described above, it is preferable to bend a linearly extending metal member along the circumferential direction of the inner cylinder to form the partition member. When this is done, the yield can be improved and costs can be reduced compared to a partition member cut from sheet metal to a shape that conforms to the outer surface of the inner cylinder. Furthermore, by bending the partition member to a size slightly smaller than the outer diameter of the inner cylinder and then expanding the partition member to attach it to the inner cylinder, the partition member can be temporarily fixed in place by the elastic force that tries to return it to its original shape, tightening against the inner cylinder and improving the workability of the installation process when attaching the partition member to the outer surface of the inner cylinder. In addition, when the metal member is bent along the circumferential direction of the inner cylinder, the metal member becomes thicker on the inner cylinder side and thinner on the outer cylinder side, making it easier for the cold heat of the refrigerant flowing through the refrigerant passage to be transferred from the partition member to the inner cylinder, thereby improving the efficiency of refrigerant transfer from the refrigerant passage to the inner cylinder.

[0012] In the ice maker configured as described above, it is preferable that the inner cylinder has a thicker section at the position where the partition member is engaged, and that an annular mounting groove is formed in the thicker section to which the partition member is engaged and attached. Although stress tends to concentrate around the annular mounting groove where the partition member is engaged, since the annular mounting groove is formed in a thicker section than the other parts, the strength around the annular mounting groove can be improved by the thicker section while maintaining high heat transfer performance of the inner cylinder without increasing the thickness between the annular mounting grooves. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram showing a cross-section of the ice-making cylinder of the ice-making machine of the present invention. [Figure 2] This is a perspective view of an inner cylinder with a partition member attached to its outer surface. [Figure 3] This is a side view of an ice-making cylinder, with the outer cylinder as a cross-section, allowing the inner cylinder and partition members to be seen. [Figure 4] This is a perspective view of an ice-making cylinder, with the inner cylinder and partition members indicated by dashed lines. [Figure 5] This is a cross-sectional view showing the connection point between the outer casing and the refrigerant inlet pipe. [Figure 6] This is a cross-sectional view showing the connection point between the outer cylinder and the refrigerant outlet pipe. [Figure 7] This is a perspective view of an ice-making cylinder with two heating and straightening sections formed in the circumferential direction of the outer cylinder. [Figure 8] This is a perspective view of an ice-making cylinder with three heating and straightening sections formed around the circumference of the outer cylinder. [Figure 9] This is a perspective view of an ice-making cylinder with four heating and straightening sections formed around the circumference of the outer cylinder. [Figure 10] This is a perspective view of an ice-making cylinder with the heating and straightening section extending circumferentially around the outer cylinder. [Figure 11] This is a partially enlarged cross-sectional view of an ice-making cylinder with thickened sections formed at the upper and lower parts of the mounting annular groove. [Modes for carrying out the invention]

[0014] An embodiment of the ice maker of the present invention will be described below with reference to the drawings. As shown in Figure 1, the ice maker 10 of this embodiment is an auger-type ice maker and includes an ice-making cylinder 20 that freezes ice-making water to produce ice, a refrigeration device 30 that cools the ice-making cylinder 20, and a water supply device 40 that supplies ice-making water to the ice-making cylinder 20. The ice-making cylinder 20 includes an inner cylinder 21, an outer cylinder 22 that is concentrically disposed outside the inner cylinder 21 and forms a refrigerant space RS through which refrigerant can pass between it and the inner cylinder 21, and a partition member 23 that is interposed between the inner cylinder 21 and the outer cylinder 22 and forms a circumferentially extending refrigerant passage RP in the refrigerant space RS.

[0015] As shown in Figure 1, the inner cylinder 21 is made from a stainless steel plate processed into a cylindrical shape (tube shape) as an example of a metal member with high strength and corrosion resistance, and is erected so that its axis is vertical. Ice-making water can be supplied into the inner cylinder 21, and the inner surface of the inner cylinder 21 is an ice-making surface where the ice-making water is frozen to make ice. An introduction section 21a into which ice-making water is introduced is provided at the bottom of the inner cylinder 21, and a water supply device 40, which will be described later, is connected to the introduction section 21a. An ice-shaving auger 24 is installed inside the inner cylinder 21 so as to be rotatable around a vertical axis, and the ice that freezes on the inner surface of the inner cylinder 21 is moved upward while being shaved off by the ice-shaving auger 24. A pressing head (fixed blade) 25 is provided at the top of the inner cylinder 21, and the ice shaved off by the ice-shaving auger 24 is pushed upward as a rod-shaped ice as it passes through the compression passage of the pressing head 25. The ice, extruded in a rod shape, is cut by a cutter 26 that rotates integrally with the ice-shaving auger 24 to form ice pieces of appropriate size. The pressing head 25 is fixed to the upper part of the inner cylinder 21 by bolts, and stress tends to concentrate around the bolt insertion holes formed in the upper part of the inner cylinder 21 when the ice shaved by the ice-shaving auger 24 passes through the compression passage of the pressing head 25. For this reason, a reinforcing member 27 is provided in the upper part of the inner cylinder 21, and the reinforcing member 27 reduces the load generated when compressing the ice passing through the compression passage of the pressing head 25 that is applied around the bolt insertion holes of the inner cylinder 21.

[0016] As shown in FIGS. 2 and 3, a plurality of annular mounting grooves 21b extending in the circumferential direction are formed on the outer peripheral surface of the inner cylinder 21, and the plurality of annular mounting grooves 21b are formed in multiple stages at equal intervals in the vertical direction. A partition member 23 is engaged with each annular mounting groove 21b, and the partition members 23 are arranged in multiple stages vertically on the outer peripheral surface of the inner cylinder 21. As shown in FIG. 3, the partition member 23 partitions the refrigerant space RS formed between the inner cylinder 21 and the outer cylinder 22 so that a refrigerant passage RP extending in the circumferential direction is formed, and a plurality of refrigerant passages RP are formed in multiple layers in the vertical direction in the refrigerant space RS by the partition member 23.

[0017] As shown in FIGS. 2 and 3, the partition member 23 is formed by bending a linearly extending metal member along the circumferential direction of the inner cylinder 21. In this embodiment, a plate-like metal member with high thermal conductivity such as a copper alloy or an aluminum alloy is used. The partition member 23 is formed by bending a linearly extending plate-like metal member into a substantially C shape with a diameter (size) slightly smaller than the diameter (size) of the annular mounting groove 21b of the inner cylinder 21 so that the thickness direction is the vertical direction. When the partition member 23 is attached to the annular mounting groove 21b of the inner cylinder 21, if the diameter of the partition member 23 is expanded and fitted into the annular mounting groove 21b of the inner cylinder 21, the partition member 23 is engaged with the annular mounting groove 21b of the inner cylinder 21 by the elastic force that tries to return to its original shape. The partition member 23 is engaged by this elastic force so as not to come off from the annular mounting groove 21b. Further, since the partition member 23 is formed by bending a metal member along the circumferential direction of the inner cylinder 21, the inner peripheral side of the partition member 23 is formed thick, and the cold and heat of the refrigerant passing through each refrigerant passage RP partitioned vertically by the partition member 23 is easily transmitted from the partition member 23 to the inner cylinder 21. Since the inner cylinder 21 does not have thickened portions above and below the position where the refrigerant space RS is formed between the inner cylinder 21 and the outer cylinder 22, the operation of moving and attaching the partition member 23 from above and below the inner cylinder 21 can be performed.

[0018] As shown in FIGS. 2 and 3, the partition member 23 has a substantially C-shaped open annular shape (open ring shape) when viewed from the vertical direction. In the partition member 23, a refrigerant passage port 23a for allowing the refrigerant to pass vertically through a part of the circumferential direction of the inner cylinder 21 is formed. The refrigerant space RS between the inner cylinder 21 and the outer cylinder 22 is partitioned vertically into multiple layers as a refrigerant passage RP extending in the circumferential direction by the partition members 23 arranged in multiple stages vertically. Each of the refrigerant passages RP partitioned vertically is communicated by the refrigerant passage port 23a. Further, the refrigerant passage ports 23a of the partition members 23 arranged in multiple stages vertically are arranged alternately so that those adjacent in the vertical direction are on the opposite sides in the radial direction, and the refrigerant passage ports 23a are arranged at positions farthest from each other vertically. The refrigerant in the refrigerant space RS flows in the circumferential direction of the inner cylinder 21 through the refrigerant passage RP, and the refrigerant flowing in the circumferential direction of the inner cylinder 21 through the refrigerant passage RP flows from the refrigerant passage port 23a into the upper refrigerant passage RP. Thus, the refrigerant flows sequentially from the lower refrigerant passage RP to the upper refrigerant passage RP, rising upward while flowing in the circumferential direction from the lower part to the upper part of the inner cylinder 21.

[0019] As shown in Figures 3 and 4, the outer cylinder 22, like the inner cylinder 21, is formed by curving a sheet metal member made of stainless steel plate, an example of a metal member with high strength and corrosion resistance, along the outer surface of the partition member 23, and wrapping it around the outside of the inner cylinder 21 to which the partition member 23 is attached. Welded joints 22a are provided to join the ends of the sheet metal member on both sides in the circumferential direction by welding, thus forming a cylindrical shape. The circumferential length of the sheet metal member constituting the outer cylinder 22 is shorter than the circumferential length of the outer surface of the partition member 23, and the welded joints 22a are formed by joining the ends of the sheet metal member on both sides in the circumferential direction with the gap filled with welding material (welding rod or other filler). The ends of the sheet metal member on both sides in the circumferential direction are formed to extend vertically parallel to the axial direction of the outer cylinder 22, and the welded joints 22a are arranged to extend vertically parallel to the axial direction of the outer cylinder 22. The ends on both sides of the sheet metal member in the circumferential direction are joined by welding material that is heated in an expanded state during the joining process. As the outer cylinder 22 shrinks when it returns to room temperature after the ends on both sides of the sheet metal member in the circumferential direction are joined by the welding material, the inner circumferential surface of the outer cylinder 22 is pressed against the outer circumference of the partition member 23, making it difficult for gaps to form. As a result, the refrigerant flowing through the refrigerant passage RP is less likely to take a shortcut between the outer cylinder 22 and the partition member 23, and instead flows through the refrigerant passage RP along the outer circumference of the inner cylinder 21.

[0020] Furthermore, the outer cylinder 22 is subjected to heat straightening, which involves expanding it by heating and then contracting it, in order to minimize gaps with respect to the partition member 23. The outer cylinder 22 is provided with a welded joint 22a, where the ends on both sides in the circumferential direction of the sheet metal member are joined by welding, and a heat straightening section 22b, which is expanded by heating and then contracted, on the radially opposite side (symmetrical to the center of the outer cylinder 22 relative to the welded joint 22a). The heat straightening section 22b is also arranged to extend vertically parallel to the axial direction of the outer cylinder 22, similar to the welded joint 22a. In this embodiment, the heat straightening section 22b is generated by heating with an electrode, and as an example, it is generated by heating with a TIG welding torch.

[0021] The outer cylinder 22 is heated not only when the welded joint 22a is joined, but the radially opposite side of the welded joint 22a is also heated by the heating and straightening section 22b. Because the outer cylinder 22 is subjected to a contracting force on both radial sides, the inner surface of the outer cylinder 22 is pressed against the outer surface of the partition member 23, making it difficult for gaps to form. Furthermore, when the heating intensity of the heating and straightening section 22b is increased, the inner surface of the outer cylinder 22 is slightly melted, causing the outer surface of the partition member 23 to bite into it. This not only prevents the refrigerant flowing through the refrigerant passage RP from passing through the space between the outer cylinder 22 and the partition member 23, but also makes it difficult for the partition member 23 to shift relative to the outer cylinder 22 due to vibration, etc. When the heating intensity of the heating and straightening section 22b is further increased to further contract the outer cylinder 22, the inner surface of the partition member 23 also bites into the annular mounting groove 21b on the outer surface of the inner cylinder 21, making it difficult for the partition member 23 to shift relative to the inner cylinder 21 due to vibration, etc.

[0022] As shown in Figures 1 and 4, a refrigerant introduction pipe 34 for introducing refrigerant into the refrigerant passage RP is connected to the lower part of the outer cylinder 22, and a refrigerant outlet pipe 35 for discharging refrigerant from the refrigerant passage RP is connected to the upper part of the outer cylinder 22. The refrigeration device 30, which will be described later, is connected to the refrigerant introduction pipe 34 and the refrigerant outlet pipe 35. As shown in Figure 5, the refrigerant introduction pipe 34 is connected in a state where it is fitted into a refrigerant inlet 22c formed in the lower part of the outer cylinder 22, and the refrigerant passing through the refrigerant introduction pipe 34 is introduced into the refrigerant passage RP from the refrigerant inlet 22c. The entire circumferential length of the refrigerant introduction pipe 34 is welded to the lower part of the outer cylinder 22, and is joined to the refrigerant inlet 22c of the outer cylinder 22 without any gaps. As shown in Figure 5A, the upper part (at least a portion) of the welded portion of the refrigerant introduction pipe 34 to the lower part of the outer cylinder 22 is at the height position where the lowest partition member 23 is located. Therefore, the lower part of the outer cylinder 22 expands at the welded joint where the refrigerant inlet pipe 34 is welded, and then contracts. As the lower part of the outer cylinder 22 contracts, it presses against the lowest partition member 23, making it difficult for a gap to form between the outer cylinder 22 and the lowest partition member 23. In the embodiment described above, the welding of the refrigerant inlet pipe 34 to the lower part of the outer cylinder 22 is not performed using welding materials such as welding rods, but this is not limited to this, and the refrigerant inlet pipe 34 and the outer cylinder 22 may be joined using welding materials such as welding rods.

[0023] As shown in Figure 6, the refrigerant outlet pipe 35 is connected to the refrigerant outlet 22d formed on the upper part of the outer cylinder 22 by being fitted into it, and the refrigerant in the refrigerant passage RP is led out from the refrigerant outlet 22d to the refrigerant outlet pipe 35. The entire circumferential length of the refrigerant outlet pipe 35 is welded to the upper part of the outer cylinder 22 and is joined to the refrigerant outlet 22d of the outer cylinder 22 without any gaps. As shown in Figure 6B, the lower part (at least a portion) of the welded portion of the refrigerant outlet pipe 35 to the upper part of the outer cylinder 22 is at the height where the uppermost partition member 23 is positioned. Therefore, the upper part of the outer cylinder 22 expands at the welded portion where the refrigerant outlet pipe 35 is welded and then contracts, and when the upper part of the outer cylinder 22 contracts, it presses against the uppermost partition member 23, making it difficult for a gap to form between the outer cylinder 22 and the uppermost partition member 23. In the embodiment described above, the welding of the refrigerant outlet pipe 35 to the upper part of the outer cylinder 22 is not performed using welding materials such as welding rods, but this is not limited to this, and the refrigerant outlet pipe 35 and the outer cylinder 22 may be joined using welding materials such as welding rods.

[0024] As shown in Figures 3 to 6, sealing members 28 are provided between the inner cylinder 21 and the outer cylinder 22 to seal the upper and lower ends of the refrigerant space RS, and the refrigerant space RS is sealed at both the top and bottom by these sealing members 28. Each of the upper and lower sealing members 28 is made of a metal annular member and has a fitting portion 28a that is fitted between the inner cylinder 21 and the outer cylinder 22, and a flange portion 28b provided above or below the fitting portion 28a. With the fitting portion 28a fitted between the inner cylinder 21 and the outer cylinder 22, the flange portion 28b is in contact with the upper or lower end of the outer cylinder 22. The sealing members 28 are fixed by welding so that no gap is created between the inner cylinder 21 and the outer cylinder 22.

[0025] As shown in Figure 1, the ice maker 10 is equipped with a refrigeration device 30 for cooling the ice-making surface on the inner circumferential surface of the inner cylinder 21. The refrigeration device 30 cools the inner cylinder 21 by the heat of vaporization that occurs when the refrigerant passes through the refrigerant passage RP in the refrigerant space RS formed between the inner cylinder 21 and the outer cylinder 22. The refrigeration device 30 includes a compressor 31 for compressing the refrigerant, a condenser 32 for cooling and liquefying the refrigerant pumped from the compressor 31, and an expansion valve 33 as an expansion means for expanding the liquefied refrigerant liquefied in the condenser 32 to low-pressure liquefied refrigerant. This low-pressure liquefied refrigerant is vaporized in the refrigerant passage RP to cool the inner cylinder 21, which functions as a cooler (evaporator). Thus, the refrigeration device 30 is configured as a refrigeration circuit by connecting the compressor 31, condenser 32, expansion valve 33, and the refrigerant passage RP, which acts as a cooler, in a ring shape with refrigerant pipes. A refrigerant introduction pipe 34 for introducing refrigerant into the refrigerant passage RP is connected to the lower part of the outer cylinder 22, and a refrigerant outlet pipe 35 for releasing refrigerant from the refrigerant passage RP is connected to the upper part of the outer cylinder 22. The refrigerant supplied in circulation by the refrigeration device 30 is introduced into the refrigerant passage RP from the refrigerant introduction pipe 34, and the refrigerant introduced into the refrigerant passage RP is released from the refrigerant outlet pipe 35.

[0026] In the refrigeration device 30, the liquefied refrigerant expanded by the expansion valve 33 is introduced into the lowest refrigerant passage RP from the refrigerant introduction pipe 34. The refrigerant introduced into the refrigerant passage RP flows along the circumferential direction of the inner cylinder 21 and is sequentially sent to the upper refrigerant passage RP through the refrigerant passage port 23a. The liquefied refrigerant passing through the refrigerant passage RP is vaporized as it is sequentially sent to the upper refrigerant passage RP through the refrigerant passage port 23a, and the ice-making surface, which is the inner circumferential surface of the inner cylinder 21, is cooled overall at the height position where the refrigerant passage RP is formed by the vaporization of the liquefied refrigerant passing through the refrigerant passage RP. The cold energy generated when the liquefied refrigerant passing through the refrigerant passage RP vaporizes is not only directly transmitted to the inner cylinder 21 but is also transmitted to the inner cylinder 21 via the partition member 23.

[0027] As shown in Figure 1, the ice maker 10 is equipped with a water supply device 40 that supplies ice-making water into the inner cylinder 21, and the water supply device 40 is connected to the inlet 21a at the bottom of the inner cylinder 21. The water supply device 40 includes an ice-making water tank 41 for storing ice-making water, a water supply pipe 42 connected from the ice-making water tank 41 to the inlet 21a, a water supply pipe 43 for supplying ice-making water into the ice-making water tank 41, and a water level sensor 44 for detecting the water level of the ice-making water in the ice-making water tank 41. The ice-making water tank 41 is positioned slightly higher than the uppermost refrigerant passage RP, that is, slightly higher than the ice-making surface of the inner cylinder 21. The water supply pipe 42 is connected to the bottom of the ice-making water tank 41, and the water supply pipe 42 is connected to the inlet 21a at the bottom of the inner cylinder 21. The ice-making water in the ice-making water tank 41 is supplied to the inner cylinder 21 through the water supply pipe 42, and the amount of ice-making water supplied to the inner cylinder 21 is the same as the water level in the ice-making water tank 41.

[0028] A water supply pipe 43 is connected to the top of the ice-making water tank 41, and a water supply valve 43a is interposed in the water supply pipe 43. By opening the water supply valve 43a, water from the water supply source is supplied to the ice-making water tank 41 through the water supply pipe 43. The ice-making water tank 41 is equipped with a water level sensor 44, which detects the water level of the ice-making water in the ice-making water tank 41. In this embodiment, the water level sensor 44 is capable of detecting a water level at the same height as the uppermost refrigerant passage RP in order to freeze the ice-making water at the ice-making surface of the inner cylinder 21. The water supply valve 43a is controlled to open and close based on the water level detected by the water level sensor 44, and the water level of the ice-making water in the ice-making water tank 41 is controlled to be at the same height as the uppermost refrigerant passage RP, i.e., the ice-making surface of the inner cylinder 21.

[0029] When ice is made using this ice maker 10, the compressor 31 of the refrigeration device 30 operates to send liquefied refrigerant into the refrigerant passage RP in the refrigerant space RS. The liquefied refrigerant vaporizes as it passes through the lower refrigerant passage RP and rises sequentially to the upper refrigerant passage RP, and the ice-making surface, which is the inner circumferential surface of the inner cylinder 21, is cooled by the heat of vaporization of the vaporized liquefied refrigerant. The ice-making water inside the inner cylinder 21 is cooled and frozen on the inner circumferential surface of the inner cylinder 21, and the ice frozen on the inner circumferential surface of the inner cylinder 21 rises while being scraped off by the rotating ice-shaving auger 24. The ice scraped off by the ice-shaving auger 24 is pushed upward as a rod-shaped ice through the compression passage of the pressing head 25, and is cut into ice pieces of appropriate size by the cutter 26.

[0030] This ice maker 10 comprises an inner cylinder 21 erected with its axial direction being vertical, an outer cylinder 22 concentrically arranged outside the inner cylinder 21 to form a refrigerant space RS through which refrigerant can pass, and a partition member 23 interposed between the inner cylinder 21 and the outer cylinder 22 to form a refrigerant passage RP extending circumferentially within the refrigerant space RS. The inner surface of the inner cylinder 21 is cooled by vaporizing the refrigerant passing through the refrigerant passage RP, and ice is made by freezing the ice-making water on the inner surface of the inner cylinder 21.

[0031] In this ice maker 10, the outer cylinder 22 is formed into a cylindrical shape by providing welded joints 22a, which are formed by welding together the ends on both sides in the circumferential direction of a sheet metal member that is curved along the outer surface of the partition member 23. Since the outer cylinder 22 is made of a sheet metal member that is curved along the outer surface of the partition member 23, it is possible to keep costs down and ensure a tight fit between the outer cylinder 22 and the outer surface of the partition member 23 with high precision compared to an outer cylinder 22 that is pre-formed into a cylindrical shape. In addition, since the outer cylinder 22 is equipped with welded joints 22a, which are formed by welding together the ends on both sides in the circumferential direction of the sheet metal member, the outer cylinder 22 shrinks after the ends on both sides in the circumferential direction of the sheet metal member is welded together, causing the outer cylinder 22 to shrink radially and tightly fit against the outer surface of the partition member 23, so that the outer cylinder 22 fits tightly against the outer surface of the partition member 23 and gaps are less likely to occur.

[0032] In this ice maker 10, the sheet metal member constituting the outer cylinder 22 has a circumferential length shorter than the circumferential length of the outer surface of the partition member 23, creating a gap between the ends on both sides in the circumferential direction. The welded joint 22a is formed by joining the sheet metal member with the ends on both sides in the circumferential direction filled with welding material. When the ends on both sides in the circumferential direction of the sheet metal member constituting the outer cylinder 22 are joined with welding material, the ends on both sides in the circumferential direction of the sheet metal member are heated together with the welding material and expand. As the ends on both sides in the circumferential direction of the sheet metal member and the welding material cool, they contract, causing the outer cylinder 22 to contract radially and adhere closely to the outer surface of the partition member 23. This makes it less likely for a gap to form between the outer cylinder 22 and the partition member 23, improving the accuracy of the adhesion between the outer cylinder 22 and the partition member 23.

[0033] In this ice maker 10, the outer cylinder 22 is provided with a heat-corrected portion 22b that is heated and thermally expanded in at least a portion of it, and then contracts. Because the outer cylinder 22 is provided with a heat-corrected portion 22b that is heated and thermally expanded in at least a portion of it and then contracts, the outer cylinder 22 contracts, improving the accuracy of its contact with the partition member 23. In this embodiment, the heat-corrected portion 22b is provided to extend vertically from the outer cylinder 22 together with the welded joint portion 22a, and is positioned on the radially opposite side of the outer cylinder 22 to the welded joint portion 22a. The outer cylinder 22 contracts from both radial sides by the welded joint portion 22a and the heat-corrected portion 22b, which improves the accuracy of the contact between the outer cylinder 22 and the partition member 23. Furthermore, when the heating intensity of the heating and straightening section 22b is increased, the inner circumferential surface of the outer cylinder 22 is slightly melted, causing the outer circumferential portion of the partition member 23 to bite into it. This not only prevents the refrigerant flowing through the refrigerant passage RP from creating a shortcut between the outer cylinder 22 and the partition member 23, but also makes the partition member 23 less likely to shift relative to the outer cylinder 22 due to vibration or the like.

[0034] In the embodiment described above, the heat straightening section 22b is provided to extend vertically along with the welded joint 22a and is located on the radially opposite side of the outer cylinder 22 to the welded joint 22a. However, multiple heat straightening sections 22b extending vertically may be provided at multiple locations in the circumferential direction of the outer cylinder 22, and the multiple heat straightening sections 22b, including the welded joint 22a, may be arranged at equal intervals in the circumferential direction of the outer cylinder 22. In Figure 7, two heat straightening sections 22b are formed in the circumferential direction of the outer cylinder 22, and the two heat straightening sections 22b, including the welded joint 22a, are arranged at 120° intervals in the circumferential direction of the outer cylinder 22. In Figure 8, three heat straightening sections 22b are formed in the circumferential direction of the outer cylinder 22, and the three heat straightening sections 22b, including the welded joint 22a, are arranged at 90° intervals in the circumferential direction of the outer cylinder 22. In Figure 9, the heat-straightening sections 22b are formed at four locations in the circumferential direction of the outer cylinder 22, and the four heat-straightening sections 22b, including the welded joint 22a, are arranged at 72° intervals in the circumferential direction of the outer cylinder 22. In this way, since the heat-straightening sections 22b, including the welded joint 22a, are arranged at equal intervals along the circumferential direction of the outer cylinder 22, the outer cylinder 22 expands uniformly throughout its entire circumferential direction due to the welded joint 22a and the multiple heat-straightening sections 22b, and then contracts. As a result, the inner circumferential surface of the outer cylinder 22 is pressed against the outer circumferential surface of the partition member 23 throughout its entire circumferential direction, making it difficult for gaps to form. Note that the heat-straightening sections 22b are not limited to being arranged at 1 to 4 locations extending vertically from the outer cylinder 22, but may be arranged at 5 or more locations extending vertically from the outer cylinder 22.

[0035] Furthermore, when forming the three heat-straightened portions 22b shown in Figure 8 on the outer circumferential surface of the outer cylinder 22, heat treatment is performed so that the heat-straightened portion 22b (shown in Figure 8a) is formed on the radially opposite side of the welded joint 22a from the outer cylinder 22, and then heat treatment is performed so that the two heat-straightened portions 22b (shown in Figure 8b and c) adjacent to the welded joint 22a are formed. When forming the four heat-straightened portions 22b shown in Figure 9 on the outer circumferential surface of the outer cylinder 22, the heat treatment is performed so that the heat-straightened portion 22b furthest from the welded joint portion 22a (shown in Figure 9a) is formed, then the heat treatment is performed so that the heat-straightened portion 22b furthest from the heat-straightened portion 22b (shown in Figure 9b) is formed, then the heat treatment is performed so that the heat-straightened portion 22b (shown in Figure 9c) furthest from the heat-straightened portion 22b (shown in Figure 9c) is formed, and finally the heat treatment is performed so that the heat-straightened portion 22b (shown in Figure 9d) furthest from the heat-straightened portion 22b (shown in Figure 9d) is formed. In this way, by performing the heat treatment to form the heat-straightened portions 22b alternately at diagonal or distant positions, similar to the bolt fastening process, the outer cylinder 22 will shrink evenly in the circumferential direction, making it less likely for a gap to form between the outer cylinder 22 and the partition member 23.

[0036] Furthermore, in Figures 2 and 7-9, the heating and straightening section 22b extends vertically from the outer cylinder 22, but in Figure 10, the heating and straightening section 22b is arranged to extend circumferentially. The heating and straightening section 22b is arranged to extend circumferentially from the outer cylinder 22 at the height position where the partition member 23 is positioned, that is, along the partition member 23. The outer cylinder 22 is caused to contract around the height portion of the partition member 23 by the heating and straightening section 22b that extends circumferentially along the partition member 23, thereby improving the accuracy of the contact between the outer cylinder 22 and the partition member 23. Note that in Figure 10, the heating and straightening section 22b is arranged at height positions corresponding to all of the partition members 23 arranged in a multi-stage vertical configuration, but this is not limited to this, and it may be arranged at height positions corresponding to some of the partition members 23 arranged in a multi-stage vertical configuration.

[0037] A refrigerant introduction pipe 34 for introducing refrigerant into the refrigerant passage RP is welded to the lower part of the outer cylinder 22. The welding material used when welding the refrigerant introduction pipe 34 to the lower part of the outer cylinder 22 is provided on the outer surface of the outer cylinder 22 at the height where the lowest partition member 23 is located. As the welding material used when welding the refrigerant introduction pipe 34 to the lower part of the outer cylinder 22 is provided at the height where the lowest partition member 23 is located, the outer cylinder 22 contracts as the welding material cools, causing the outer cylinder 22 to adhere closely to the outer surface of the lowest partition member 23, making it less likely for gaps to form and improving the accuracy of the adhesion between the outer cylinder 22 and the partition member 23.

[0038] Similarly, a refrigerant outlet pipe 35 for guiding refrigerant from the refrigerant passage RP is welded to the upper part of the outer cylinder 22, and the welding material used when welding the refrigerant outlet pipe 35 to the upper part of the outer cylinder 22 is provided on the outer surface of the outer cylinder 22 at the height position where the uppermost partition member 23 is located. As the welding material used when welding the refrigerant outlet pipe 35 to the upper part of the outer cylinder is provided at the height position where the uppermost partition member 23 is located, the outer cylinder 22 shrinks as the welding material cools, causing the outer cylinder 22 to adhere closely to the outer surface of the uppermost partition member 23, making it less likely for gaps to form and improving the accuracy of the adhesion between the outer cylinder 22 and the partition member 23.

[0039] Since the partition member 23 is made by bending a linearly extending metal member along the circumferential direction of the inner cylinder, the yield can be improved and costs reduced compared to a partition member 23 cut from sheet metal to a shape that conforms to the outer surface of the inner cylinder 22. Furthermore, by bending the partition member 23 to a size slightly smaller than the outer diameter of the inner cylinder 21 and then expanding the partition member 23 and attaching it to the inner cylinder 21, the partition member 23 can be temporarily fixed in place by tightening it against the inner cylinder 21 due to its elastic force trying to return to its original shape, improving the workability of the installation process when attaching the partition member 23 to the outer surface of the inner cylinder 21. In addition, when the metal member is bent along the circumferential direction of the inner cylinder 21, the metal member becomes thicker on the inner cylinder 21 side and thinner on the outer cylinder side, making it easier for the cold heat of the refrigerant flowing through the refrigerant passage RP to be transferred from the partition member 23 to the inner cylinder 21, thereby improving the efficiency of refrigerant transfer from the refrigerant passage RP to the inner cylinder 21.

[0040] In the embodiment described above, the inner cylinder 21 has multiple annular mounting grooves 21b formed vertically and horizontally, into which the partition members 23 are engaged (fitted), and the partition members 23 are engaged with each annular mounting groove 21b of the inner cylinder 21. The partition members 23 are arranged at equal intervals in the height direction of the inner cylinder 21 by engaging with the annular mounting grooves 21b of the inner cylinder 21, and a refrigerant passage RP is formed vertically and horizontally and horizontally between the inner cylinder 21 and the outer cylinder 22. In the embodiment shown in Figure 11, the inner cylinder 21 has a thickened portion 21c at the position where the partition members 23 are engaged, and an annular mounting groove 21b is formed in the thickened portion 21c into which the partition members 23 are engaged and attached. Thickened portions 21c are formed on the upper and lower sides of the annular mounting groove 21b, which are thicker than the thickness of the inner cylinder 21, and furthermore, the portion in which the annular mounting groove 21b is formed is thicker than the thickness of the inner cylinder 21 other than the thickened portion 21c. Although stress tends to concentrate around the annular mounting groove 21b to which the partition member 23 is engaged, the annular mounting groove 21b is formed as a thickened portion 21c with a greater thickness than other parts. Therefore, the strength around the annular mounting groove 21b can be improved by the thickened portion 21c while maintaining high heat transfer performance of the inner cylinder 21 without increasing the thickness between the annular mounting groove 21b and the annular mounting groove 21b. Furthermore, because the annular mounting groove 21b is formed as a thickened portion 21c, the thickness of the upper or lower part of the inner cylinder 21 can be increased to reinforce the upper and lower parts of the inner cylinder 21, but within a range that does not exceed the thickness of the thickened portion 21c.

[0041] In the above-described embodiment, the partition member 23 has a roughly C-shape, which is an open annular shape when viewed from the vertical direction, and a refrigerant passage opening 23a is formed in a part of the circumferential direction of the inner cylinder 21 to allow the refrigerant to pass up and down. However, the embodiment is not limited to this, and the partition member 23 may have a closed annular shape when viewed from the vertical direction, and a refrigerant passage opening may be formed by a recess or opening through which the refrigerant can pass up and down. Furthermore, in the above-described embodiment, the partition member 23 is used to form a refrigerant passage RP extending in the circumferential direction, but the embodiment is not limited to this, and the partition member may be arranged to spirally wrap between the inner cylinder 21 and the outer cylinder 22 to form a spiral refrigerant passage.

[0042] The ice maker in the embodiment described above is an auger-type ice maker, but is not limited to this. Any ice maker equipped with a cylindrical ice-making cylinder 20 is acceptable, and it may also be a slurry-type ice maker or a drum-type ice maker. [Explanation of Symbols]

[0043] 10...Ice maker, 21...Inner cylinder, 21b...Annular mounting groove, 21c...Thick-walled section, 22...Outer cylinder, 22a...Welded joint section, 22b...Heated straightening section, 23...Partition member, RS...Refrigerant space, RP...Refrigerant passage.

Claims

1. An inner cylinder erected so that its axis is in the vertical direction, An outer cylinder is concentrically disposed on the outside of the inner cylinder and forms a refrigerant space between itself and the inner cylinder through which the refrigerant can pass; The system includes a partition member interposed between the inner cylinder and the outer cylinder to form a circumferentially extending refrigerant passage within the refrigerant space, An ice maker that cools the inner surface of the inner cylinder by vaporizing the refrigerant passing through the refrigerant passage, and freezes ice-making water on the inner surface of the inner cylinder to make ice, The ice maker is characterized in that the outer cylinder is formed in a cylindrical shape by providing welded joints where the ends on both sides in the circumferential direction of a sheet metal member curved along the outer surface of the partition member are joined by welding.

2. In the ice maker according to claim 1, The sheet metal member has a circumferential length shorter than the circumferential length of the outer surface of the partition member, and a gap is formed between the ends on both sides in the circumferential direction. The ice maker is characterized in that the welded joint is formed by joining the circumferential ends of the sheet metal member with the gaps filled by welding material.

3. In the ice maker according to claim 1 or 2, The ice maker is characterized in that the outer cylinder is equipped with a heating and straightening section that expands and then contracts after being heated in at least a portion of it.

4. In the ice maker described in claim 3, The ice maker is characterized in that the heating and straightening section is provided together with the welded joint so as to extend vertically from the outer cylinder, and is positioned on the side of the outer cylinder opposite to the welded joint in the radial direction.

5. In the ice maker described in claim 3, The aforementioned heat straightening section extends vertically along the outer cylinder together with the welded joint section and is arranged at multiple locations in the circumferential direction of the outer cylinder. An ice maker characterized in that these multiple heating and straightening sections are arranged at equal intervals in the circumferential direction of the outer cylinder, including the welded joints.

6. In the ice maker described in claim 3, The ice maker is characterized in that the heating and straightening section is arranged to extend circumferentially along the partition member of the outer cylinder.

7. In the ice maker according to claim 1 or 2, A refrigerant introduction pipe for introducing refrigerant into the refrigerant passage is welded to the lower part of the outer cylinder. An ice maker characterized in that at least a portion of the welding point of the refrigerant introduction pipe to the lower part of the outer cylinder is at the height where the partition member is positioned.

8. In the ice maker according to claim 1 or 2, A refrigerant outlet pipe for discharging refrigerant from the refrigerant passage is welded to the upper part of the outer cylinder. An ice maker characterized in that at least a portion of the welding points of the refrigerant outlet pipe to the upper part of the outer cylinder is at the height where the partition member is positioned.

9. In the ice maker according to claim 1 or 2, The ice maker is characterized in that the partition member is a metal member that extends in a straight line and is bent along the circumferential direction of the inner cylinder.

10. In the ice maker according to claim 9, The ice maker is characterized in that the inner cylinder has a thickened portion at the position where the partition member is engaged, and an annular mounting groove is formed in the thickened portion to which the partition member is engaged and attached.

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