DESC:COOLING PLATE FOR BATTERY PACK
CROSS REFERENCE TO RELATED APPLICTIONS
The present application claims priority from Indian Provisional Patent Application No. 202221074283 filed on 21/12/2022, the entirety of which is incorporated herein by a reference.
TECHNICAL FIELD
The present disclosure generally relates to battery pack cooling. The present disclosure specifically relates to a cooling plate for a battery pack. Furthermore, the present disclosure relates to a battery pack with a cooling plate.
BACKGROUND
Recently, there has been a rapid development in battery packs because of their use as clean energy storage solution for various uses ranging from domestic use to transportation use. The battery pack comprises a set of any number of identical batteries or individual battery cells. The battery cells are assembled as cell arrays and multiple cell arrays are combined to form the battery packs.
Each battery pack comprises a plurality of cells and cell holders for securing the plurality of cells. These battery cells are electrically connected to form cell arrays and multiple cell arrays can be stacked together to form the battery pack, being used as a single unit for meeting high voltage and current requirements. However, the battery pack generates a large amount of heat during the charging and discharging process. If heat generated during the charging and discharging process is not effectively eliminated, heat accumulation may occur inside the battery, which results in accelerated deterioration of the battery cells. Moreover, in some conditions such heat accumulation may even lead to hotspots causing thermal runaway which would permanently damage the battery pack. Furthermore, the thermal runaway may lead to fire and/or explosion causing safety risks.
Generally, to eliminate the heat and prevent resultant damages, a cooling jacket is placed on the outer surfaces such as the casing of the battery pack. However, such a cooling structure can only extract heat from the outer portions of the battery pack, leaving the inner portions of the battery pack at a higher temperature. Thus, a temperature gradient is formed between the inner and outer portion of the battery pack which leads to poor cell performance and higher degradation rate. To reduce the temperature gradient and extract heat from the inner portions of the battery pack, a submerged cooling technique is used wherein all the battery cells of the battery pack are submerged in a coolant. The battery pack with coolant-submerged battery cells have a lower temperature gradient between the outer and inner portions of the battery pack. However, the use of such a cooling technique leads to an increase in the weight of the battery pack. Furthermore, the size and cost of the battery pack is also increased significantly. Moreover, such cooling techniques add unnecessary bulk to the already bulky battery pack. Furthermore, the added weight and size affects the performance of the battery pack in mobile application such as electric vehicles.
Thus, there exists a need for an efficient cooling mechanism capable of quickly dissipating heat generated during the charging and discharging operation of the battery pack and overcomes one or more problems associated as set forth above.
SUMMARY
An object of the present disclosure is to provide a cooling plate for a battery pack.
Another object of the present disclosure is to provide a battery pack comprising a cooling plate for efficient cooling of battery cells.
In accordance with first aspect of the present disclosure, there is provided a cooling plate for a battery pack. The cooling plate comprises a first plate and a second plate. The first plate comprises a first engagement portion forming a coolant flow path in the first plate. The second plate comprises a second engagement portion, wherein the first engagement portion is engaged with the second engagement portion to form the cooling plate for the battery pack.
The present disclosure provides a cooling plate for a battery pack. The cooling plate, as disclosed in the present disclosure is advantageous in terms of compactness of size. Furthermore, the cooling plate of the present disclosure is advantageous in terms of being lightweight. Furthermore, the cooling plate of the present disclosure adds less weight and bulk to the battery pack compared to conventional cooling mechanisms. Furthermore, the cooling plate of the present disclosure is advantageous in terms of providing better heat dissipation leading to improved battery pack health and longer operational life. Moreover, the cooling plate of the present disclosure is advantageous in terms of efficiently extracting heat from inside the battery pack.
In accordance with second aspect of the present disclosure, there is provided a battery pack. The battery pack comprises a plurality of battery cells, at least one cell holder, and a cooling plate. The cooling plate comprises a first plate and a second plate. The first plate comprises a first engagement portion forming a coolant flow path in the first plate. The second plate comprises a second engagement portion, wherein the first engagement portion is engaged with the second engagement portion to form the cooling plate for the battery pack.
Additional aspects, advantages, features, and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative embodiments constructed in conjunction with the appended claims that follow.
It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.
Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:
Figure 1 illustrates an exploded view of a cooling plate for a battery pack, in accordance with an aspect of the present disclosure.
Figure 2 illustrates a top view of the first plate of the cooling for the battery pack, in accordance with an aspect of the present disclosure.
Figure 3 illustrates a top view of the second plate of the cooling plate for the battery pack, in accordance with an embodiment of the present disclosure.
In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
DETAILED DESCRIPTION
The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.
The description set forth below in connection with the appended drawings is intended as a description of certain embodiments of a cooling plate of a battery pack and is not intended to represent the only forms that may be developed or utilized. The description sets forth the various structures and/or functions in connection with the illustrated embodiments; however, it is to be understood that the disclosed embodiments are merely exemplary of the disclosure that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
While the disclosure is susceptible to various modifications and alternative forms, specific embodiment thereof has been shown by way of example in the drawings and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.
The terms “comprise”, “comprises”, “comprising”, “include(s)”, or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a setup, or system that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or system. In other words, one or more elements in a system or apparatus preceded by “comprises... a” does not, without more constraints, preclude the existence of other elements or additional elements in the system or apparatus.
In the following detailed description of the embodiments of the disclosure, reference is made to the accompanying drawings which are shown by way of illustration-specific embodiments in which the disclosure may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.
The present disclosure will be described herein below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the description with unnecessary detail.
As used herein, the terms “battery pack”, “battery”, and “power pack” are used interchangeably and refer to multiple individual battery cell arrays connected to provide a higher combined voltage or capacity than what a single battery cell array can offer. The battery pack is designed to store electrical energy and supply it as needed to various devices or systems. Battery packs, as referred herein may be used for various purposes such as power electric vehicles and other energy storage applications. Furthermore, the battery pack may include additional circuitry, such as a battery management system (BMS), to ensure the safe and efficient charging and discharging of the battery cells. The battery pack comprises a plurality of battery cell arrays which in turn comprises a plurality of battery cells.
As used herein, the term “battery cell array” refers to an assembled unit of a plurality of cylindrical battery cells that are connected physically and electrically to form a larger energy storage system. Each cell within the battery cell array is typically a discrete unit capable of storing electrical energy. The battery cell array can be arranged in series or parallel configuration depending on the desired voltage and capacity requirements. It is understood that connecting the battery cell array in series increases the overall voltage of the battery pack while connecting them in parallel increases the capacity. The electrical connections in the battery cell array are formed by connecting the terminals of the battery cells with bus bars. Furthermore, in addition to the individual cells, a battery pack may also include circuitry for balancing the charge levels of the cells, managing the charging and discharging processes, and providing safety features such as overcharge and over-discharge protection. The battery cell array, along with the associated electronics and packaging, forms the core component of a battery pack, enabling the efficient and reliable storage and delivery of electrical energy.
As used herein, the term “cooling plate” and “thermal cooling plate” are used interchangeably and refers to a structure that is used to dissipate heat generated during the operation of the battery cells in the cell array. It would be understood that the cooling plate is designed to maintain optimal temperature levels within the cell array, preventing excessive heat build-up that can affect the performance, lifespan, and safety of the battery cells. The cooling plate may include a metal heat spreader, liquid cooling plate, finned cooling plate, and so forth.
As used herein, the terms “battery cell”, “cells” and “battery-cell” are used interchangeably and refer to a basic energy storage unit that stores electrical energy. The battery cells may be comprised of different chemistry including lithium-ion cells, solid-state cells, zinc-carbon and alkaline cells, nickel metal hydride, nickel-cadmium, and so forth. Furthermore, the battery cells may include various types (based on the shape) of cells including cylindrical cells, prismatic cells, pouch cells, coin cells, or any customized shape cells.
As used herein, the terms “cell holder” and “holder” are used interchangeably and refer to a component of the battery pack used to securely hold and position individual battery cells within the battery pack. The primary purpose of a cell holder is to provide mechanical support and protection for the battery cells. It helps maintain the structural integrity of the battery pack, preventing cells from shifting or coming into contact with each other, which could cause damage or safety hazards. It would be appreciated that the cell holders are crucial in ensuring the proper assembly, alignment, and electrical connectivity of battery cells within the cell array and the battery pack. They contribute to the overall reliability, safety, and performance of the battery pack by preventing cell damage, maintaining consistent contact, and facilitating efficient power transfer.
As used herein, the term “first plate” refers to a panel of the cooling plate that forms one of the exterior cooling surfaces of the cooling plate. The first plate may be made up of at least one of: a metal, an alloy, a composite, or a combination thereof, which is suitable for thermal conduction. Moreover, the first plate may be electrically insulating.
As used herein, the term “first engagement portion” refers to an interior surface area of the first plate that engages with other components of the cooling plate.
As used herein, the term “second plate” refers to a flat panel of the cooling plate that forms another exterior cooling surface of the cooling plate. The second plate may be made up of at least one of: a metal, an alloy, a composite, or a combination thereof, which is suitable for thermal conduction. Moreover, the second plate may be electrically insulating.
As used herein, the term “second engagement portion” refers to an interior surface area of the second plate that engages with other components of the cooling plate.
As used herein, the terms “channel boundary”, and “at least one channel boundary” are used interchangeably and refer to perpendicularly protruding elements on the first plate that creates a defined path in the cooling plate for the flow of coolant.
As used herein, the term “engagement groove” refers to recessed portions on the top surface of at least one channel boundary. The engagement groove receives a complementary element of the second plate of the cooling plate such that the first plate and the second plate are fixed together to form the cooling plate.
As used herein, the term “engagement projection” refers to projected portions on the second plate complementary to the engagement grooves present on the top surface of at least one channel boundary. The engagement projections lock in the engagement grooves to join the first plate and the second plate forming the cooling plate.
As used herein, the term “coolant” refers to a fluid used to regulate the temperature of the battery pack. The coolant absorbs heat from the battery pack and dissipates it outside the battery pack.
As used herein, the term “coolant inlet” refers to an opening in the cooling plate for entry of the coolant in the cooling plate for absorbing heat from the battery pack.
As used herein, the term “coolant outlet” refers to an opening in the cooling plate for the exit of the coolant from the cooling plate after absorbing heat from the battery pack.
As used herein, the term “connector” refers to a mechanical device that joins the coolant inlet and coolant outlet of the cooling plate to the coolant supply unit. The connector may be connected to at least one tube to enable the flow of coolant between the cooling plate and the coolant supply unit.
As used herein, the term “coolant supply unit” refers to a system that stores, circulates, and conditions coolant for the cooling of the battery pack. The coolant supply unit may comprise a coolant reservoir, a coolant pump, and a heat exchanger to extract heat from the battery pack.
As used herein, the terms “coolant flow path” “coolant flow channel” and “coolant channel” are used interchangeably and refer to the structure in the cooling plate that forms a pathway for the flow of coolant. The flow of coolant is used to dissipate the heat from the plurality of battery cells and ensure optimum operation.
As used herein, the term “busbar” refers to a conductive metal strip or plate used to facilitate the distribution of electrical power or signals within the cell arrays of the battery pack. The bus bar plate serves as a common electrical connection point for multiple battery cells.
As used herein, the term “thermal cooling pad” and “cooling pad” are used interchangeably and refers to a soft, compressible material used to enhance heat transfer between two surfaces. It is to be understood that the thermal cooling pad fills in microscopic air gaps and uneven surfaces between the heat source and the heat sink, ensuring efficient heat transfer and minimizing thermal resistance. By improving the contact between the two surfaces, the thermal cooling pad enhances the conduction of heat from the heat-generating component to the heat sink, allowing for more effective cooling.
Figure 1, in accordance with an embodiment, describes an exploded view of a cooling plate 100 for a battery pack. The cooling plate 100 comprises a first plate 102 and a second plate 106. The first plate 102 comprises a first engagement portion 104 forming a coolant flow path 122 in the first plate 102. The second plate 106 comprises a second engagement portion 108, wherein the first engagement portion 104 is engaged with the second engagement portion 108 to form the cooling plate 100 for the battery pack.
The present disclosure provides the cooling plate 100 for the battery pack. The cooling plate 100 is advantageous in terms of compactness of size. Furthermore, the cooling plate 100 is advantageous in terms of being lightweight. Furthermore, the cooling plate 100 adds less weight and bulk to the battery pack compared to conventional cooling mechanisms. Furthermore, the cooling plate 100 is advantageous in terms of providing better heat dissipation leading to improved battery pack health and longer operational life. Moreover, the cooling plate 100 is advantageous in terms of efficiently extracting heat from inside the battery pack. Beneficially, the cooling plate 100 is located inside the battery pack to extract heat from inside the battery pack. Furthermore, beneficially the cooling plate 100 is in physical contact with a plurality of battery cells of the battery pack for efficient heat transfer from the plurality of battery cells to a coolant flowing inside the cooling plate 100.
It is to be understood that the first engagement portion 104 of the first plate 102 is engaged with the second engagement portion 108 of the second plate 106 to join them together forming the cooling plate 100 for the battery pack.
Figure 2, in accordance with an embodiment, describes the first plate 102. In an embodiment, the first engagement portion 104 comprises at least one projecting channel boundary 110 forming the coolant flow path 122. Beneficially, the projecting channel boundary 110 is designed to form the coolant flow path 122 which is leakproof. Beneficially, the projecting channel boundary 110 prevents leakage of the coolant from the cooling plate 100 inside the battery pack.
In an embodiment, the first engagement portion 104 comprises at least one engagement groove 112 on the at least one projecting channel boundary 110. Beneficially, the at least one engagement groove 112 enables the locking of the second engagement portion 108 to the first engagement portion 104 for joining the first plate 102 and the second plate 106.
Figure 3, in accordance with an embodiment, describes the second plate 106. In an embodiment, the second engagement portion 108 comprises at least one engagement projection 114 complementary to the at least one engagement groove 112 of the at least one projecting channel boundary 110. Beneficially, the at least one engagement projection 114 enables the locking of the second engagement portion 108 to the first engagement portion 104 for joining the first plate 102 and the second plate 106.
In an embodiment, the first engagement portion 104 is engaged with the second engagement portion 108 by locking the at least one engagement projection 114 in the at least one engagement groove 112 to form the cooling plate 100 for the battery pack. Beneficially, the at least one engagement projection 114 securely locks in the at least one engagement groove 112 to join the first plate 102 and the second plate 106. More beneficially, the at least one engagement projection 114 securely locks in the at least one engagement groove 112 to enclose the at least one projecting channel boundary 110 to form the coolant flow path 122. More beneficially, the at least one engagement projection 114 securely locks in the at least one engagement groove 112 to ensure the proper alignment of the first plate 102 and the second plate 106 of the cooling plate 100. More beneficially, the at least one engagement projection 114 securely locks in the at least one engagement groove 112 to prevent the dislocation, disengagement, and misalignment of the first plate 102 and the second plate 106 of the cooling plate 100.
In an embodiment, at least one of the first plate 102 and the second plate 106 comprises a coolant inlet 116 for entry of a coolant in the coolant flow path 122. Beneficially, the coolant inlet 116 is present at one end of the coolant flow path 122 to enable the entry of the coolant in the coolant flow path 122 for extracting heat from the inside of the battery pack.
In an embodiment, at least one of the first plate 102 and the second plate 106 comprises a coolant outlet 118 for the exit of coolant from the coolant flow path 122. Beneficially, the coolant outlet 118 is present at another end of the coolant flow path 122 to enable the exit of the coolant from the coolant flow path 122 for extracting heat from the inside of the battery pack.
In an embodiment, the cooling plate 100 comprises a connector 120 fixed with the coolant inlet 116 and the coolant outlet 118, wherein the connector 120 connects the coolant inlet 116 and the coolant outlet 118 to a coolant supply unit. Beneficially, the connector securely connects the coolant inlet 116 and the coolant outlet 118 to a coolant supply unit. It is to be understood that the coolant supply unit may comprise at least one of: a reservoir, a pump, and a heat exchanger. The pump of the coolant supply unit supplies coolant to the cooling plate 100. The supplied coolant enters the cooling plate 100 through the coolant inlet 116 via the connector 120. The coolant flows through the coolant flow path 122 extracting heat from the plurality of battery cells and exits through the coolant outlet 118 via the connector 120.
In an embodiment, the first engagement portion 104 comprises a sealant lining on the at least one projecting channel boundary 110. Beneficially the sealant lining prevents leakage of the coolant from the coolant flow path 122 inside the battery pack.
In an embodiment, the cooling plate 100 comprises the first plate 102 and the second plate 106. The first plate 102 comprises the first engagement portion 104 forming the coolant flow path 122 in the first plate 102. The second plate 106 comprises the second engagement portion 108, wherein the first engagement portion 104 is engaged with the second engagement portion 108 to form the cooling plate 100 for the battery pack. Furthermore, the first engagement portion 104 comprises the at least one projecting channel boundary 110 forming the coolant flow path 122. Furthermore, the first engagement portion 104 comprises the at least one engagement groove 112 on the at least one projecting channel boundary 110. Furthermore, the second engagement portion 108 comprises the at least one engagement projection 114 complementary to the at least one engagement groove 112 of the at least one projecting channel boundary 110. Furthermore, the first engagement portion 104 is engaged with the second engagement portion 108 by locking the at least one engagement projection 114 in the at least one engagement groove 112 to form the cooling plate 100 for the battery pack. Furthermore, at least one of the first plate 102 and the second plate 106 comprises the coolant inlet 116 for entry of the coolant in the coolant flow path 122. Furthermore, at least one of the first plate 102 and the second plate 106 comprises the coolant outlet 118 for the exit of coolant from the coolant flow path 122. Furthermore, the cooling plate 100 comprises the connector 120 fixed with the coolant inlet 116 and the coolant outlet 118, wherein the connector 120 connects the coolant inlet 116 and the coolant outlet 118 to the coolant supply unit. Furthermore, the first engagement portion 104 comprises the sealant lining on the at least one projecting channel boundary 110.
In accordance with second aspect of the invention, there is described a battery pack comprising a plurality of battery cells, at least one cell holder, and a cooling plate 100. The cooling plate 100 comprises a first plate 102 and a second plate 106. The first plate 102 comprises a first engagement portion 104 forming a coolant flow path 120 in the first plate 102. The second plate 106 comprises a second engagement portion 108, wherein the first engagement portion 104 is engaged with the second engagement portion 108.
Beneficially, the coolant flows in the concealed coolant flow path 122 absorbing the heat generated from the plurality of battery cells. The heat-absorbed coolant flows out of the concealed coolant flow path 122 resulting in the cooling of the battery pack.
In an embodiment, the battery pack comprises a plurality of busbars. Beneficially, the plurality of the busbars electrically connects the plurality of battery cells in the battery pack.
In an embodiment, the battery pack comprises thermal cooling pads, and wherein each of the thermal cooling pad is mounted over each of the busbars to create thermal cooling of the busbar plates and terminals of the plurality of battery cells. Beneficially, the thermal cooling pads enable the cooling of the plurality of busbars and terminals of the plurality of battery cells.
Beneficially, in the presently disclosed battery pack, the plurality of battery cells are efficiently cooled at both ends, wherein one end of the plurality of battery cells is cooled by the cooling plate 100 and the other end of the plurality of battery cells is cooled by the thermal cooling pads.
In the description of the present invention, it is also to be noted that, unless otherwise explicitly specified or limited, the terms “disposed,” “mounted,” and “connected” are to be construed broadly, and may for example be fixedly connected, detachably connected, or integrally connected, either mechanically or electrically. They may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases by those skilled in the art.
Modifications to embodiments and combinations of different embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as “including”, “comprising”, “incorporating”, “have”, and “is” used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural where appropriate.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the present disclosure, the drawings, and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
,CLAIMS:1. A cooling plate (100) for a battery pack, the cooling plate (100) comprises:
- a first plate (102), comprising a first engagement portion (104) forming a coolant flow path (122) in the first plate (102); and
- a second plate (106) comprising a second engagement portion (108),
wherein the first engagement portion (104) is engaged with the second engagement portion (108) to form the cooling plate (100) for the battery pack.
2. The cooling plate (100) as claimed in claim 1, wherein the first engagement portion (104) comprises at least one projecting channel boundary (110) forming the coolant flow path (122).
3. The cooling plate (100) as claimed in claim 1, wherein the first engagement portion (104) comprises at least one engagement groove (112) on the at least one projecting channel boundary (110).
4. The cooling plate (100) as claimed in claim 1, wherein the second engagement portion (108) comprises at least one engagement projection (114) complementary to the at least one engagement groove (112) of the at least one projecting channel boundary (110).
5. The cooling plate (100) as claimed in claim 1, wherein the first engagement portion (104) is engaged with the second engagement portion (108) by locking the at least one engagement projection (114) in the at least one engagement groove (112) to form the cooling plate (100) for the battery pack.
6. The cooling plate (100) as claimed in claim 1, wherein at least one of the first plate (102) and the second plate (106) comprises a coolant inlet (116) for entry of a coolant in the coolant flow path (122).
7. The cooling plate (100) as claimed in claim 1, wherein at least one of the first plate (102) and the second plate (106) comprises a coolant outlet (118) for exit of coolant from the coolant flow path (122).
8. The cooling plate (100) as claimed in claim 1, wherein the cooling plate (100) comprises a connector (120) fixed with the coolant inlet (116) and the coolant outlet (118), wherein the connector (120) connects the coolant inlet (116) and the coolant outlet (118) to a coolant supply unit.
9. The cooling plate (100) as claimed in claim 1, wherein the first engagement portion (104) comprises a sealant lining on the at least one projecting channel boundary (110).
10. A battery pack comprising:
- a plurality of battery cells;
- at least one cell holder; and
- a cooling plate (100), comprising:
- a first plate (102), comprising a first engagement portion (104) forming a coolant flow path (120) in the first plate (102); and
- a second plate (106) comprising a second engagement portion (108),
wherein the first engagement portion (104) is engaged with the second engagement portion (108).